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Converting the floor plan from #26-3 to #26-10

Converting the floor plan from #26-3 to #26-10

When we bought the GMC, a 1976 Eleganza II, it was a pretty vanilla version of a GMC Motorhome. We used it that way for about the first 4 years of ownership. About 7 years ago, in 2010, we removed the side-facing setees and converted the back section into a permanent bed. We also removed the dinette that converted into a double bed and replaced it with a couple of Honda Odyssey middle bucket seats and a round table. The davo on the driver’s side that converted into a bunk bed was removed in favor of a sofa that I made from wood with two large and very useful drawers under it.

We used the coach that way until about a year ago – mid-2016 – when we started sleeping in separate beds, mostly because of the difficulty of getting in and out during the night. When this started I added the ability to convert the sofa into a standard-sized twin bed by topping it with a folding piece of plywood that allowed the seat and back cushions to combine and form the mattress. This made a comfortable bed but we don’t like sleeping separately.

On our trip to Coos Bay in September of 2016 we lost our engine and had a two-week adventure installing a “new” one. One of the reactions to this incident was a loss of faith in the GMC and the expressed desire (by some of us) to give up on the GMC and find something more reliable. We did shop around and convince ourselves that there was nothing like a GMC available – considering size, floor plans, and cost ($100K is a good estimate). Reliability is always and issue but the floor plans were the biggest issue and some of the ones that might have filled the bill had twin beds which made us reconsider them as an alternative to one big bed.

With twin beds becoming an alternative we took another look at the GMC and saw some new possibilities. Carol, from day 1, loved the idea of a dinette in the back where the permanent bed now was. When we bought the coach the side-facing setees were set up and looked very inviting with that giant rear window. There was no table back there and I doubt it ever had one but we could imagine it. We decided to remove the permanent bed to install our own version of a rear dinette and to remove the bucket-seat dinette (which we had come to dislike a little anyway) and replace it with a mirror-image couch like the one I had been sleeping on. With both couch/beds open for sleeping there would be about 14 inches of space between them – plenty of space to allow getting in and out of bed during the night without disturbing each other. The benefit of using the areas in front of the entry door and the kitchen for the twin beds is that there is more room for slightly longer beds

Insulating the fuel tanks

Insulating the fuel tanks

Hot fuel is a big problem with GMCs. Not only does it cause what I call “the vapors” (vapor lock is a specific type of vapor-caused failure which we don’t really see) but boiling fuel is corrosive and dangerous. It has twice peeled the paint around the fuel-fill opening on my new paint job. In October, on our return trip from our attempt to get to Coos Bay we were driving on the Interstate in Southern Arizona with the outside air temperature at 93 degrees Fahrenheit and we smelled gasoline. I pulled over to see what was happening and heard my gas cap venting – again! I took my laser IR temperature gun and found that the front of the front fuel tank was 155 degrees and the bottoms of both tanks were 139 degrees. In putting together a seminar about “the vapors” a couple of years ago I found that “Winter” gas can boil at about 140 degrees.

The heat that elevated the tank temperatures from the ambient 93 degrees to 155 degrees is coming from the engine compartment, the exhaust system, and the hot asphalt which is only about a foot away. The engine, using the FiTech EFI and Fuel Command Center, was running great but the fuel was producing lots of vapor. The usual story line is that the fuel/vapor separator and the charcoal canister are supposed to take care of that vapor and you should never have pressure in your tanks and definitely not be venting through your gas cap. If you do develop pressure in your tanks you must have a blocked vent line the story goes.

I think that is BS. The opening in the fuel/vapor separator is about 1/16″, maybe slightly more but not much. I opened mine when I got home from that trip because I thought there must be something wrong with it. There is, it is inadequate for today’s fuels and the GMC’s design. There are approximately 20 square feet of fuel in those tanks and that much boiling fuel cannot be adequately vented through a 1/16″ opening – that is obvious to me. The gas cap is designed to vent at 2 PSI (minimum) for safety reasons.

My friend, neighbor and fellow GMCer, Dan Gibb came up with the idea to insulate the tanks with a modern high-tech material called Ceramic Fiber Blanket Insulation and some roofing metal panels. We had heard of some other GMCer who covered his tanks with aluminum diamond plate and claimed it had solved his vapor problems. Dan found and bought all of the materials for the project (both his and my coaches) and we made the panels and installed them on my coach this week. It took two of us about 16 hours to make all 4 panels and to install them on my coach – Dan has a newly discovered fuel leak that has to get fixed first. [Note: long after installing the insulation I developed a leak in my rear air suspension system. Turns out we nicked the air tubing while installing the tin material eventually causing a significant leak. Fixed by replacing all three lines from that point to the driver’s side air bag.]

Below are photos of our project. The photos of the uninstalled panels and the drawing are by Dan. The panels will be installed in his coach after a recently discovered fuel leak is fixed: 

 

 

FiTech Notes – updated January 24, 2017

FiTech Notes – updated January 24, 2017
1/24/2017

Please note that the adjusting screw on the FiTech unit that is manipulated during the IAC Steps setting is the screw on the left side in FRONT of the throttle body – NOT the one on the left side that controls the butterflies.

11/12/2016 – Changing settings using the Handheld display

If you are changing parameters using the handheld unit you must do a “send to ECU” for each individual change on a screen. If you do not do that only the last change made on a screen will be sent. I verify each change with a “read from ECU” right after I make it.

11/9/2016 – Making changes to fix poor idle and stalls with advice from Randy VanWinkle

I have talked with several who have recently installed the FiTech and they have been having some problems with a good idle and with some hesitation / stumble at initial tip-in and during transition from coasting back to acceleration. Armand Minnie sent me a log capturing some of his issues including an occasional stall. In looking at the log, it showed that the AFR was pretty rich most of the time. When I install the FiTech, I noticed that the AFR settings for idle, cruise (1100, 3000 & 6000 rpm), as well as WOT were set by default too rich for our engines. The FiTech system is targeted at the hotrodding crowd that run aggressive cams and generally are wanting to be much richer so the engine will idle and cruise smoothly. Our engines run quite well at close to Stoichiometric (14.7 to 1 AFR). So for my install before I started, I changed the AFR values. I set the idle AFR to 14.5 erring toward the rich side. For cruise AFR, I set the value to 14.7. I think you could go slightly more lean but not really knowing the FiTech, I didn’t want to go any leaner at cruise unless I could monitor exhaust gas temperatures and because I wasn’t going to see this install after I left, I stayed conservative. I believe I set WOT AFR to 12.8. This guy I did the install for wasn’t going to be in the mountains with long hard pulls so I didn’t worry too much about this value. If you anticipate doing any mountain driving that will have long hard pulls, I would consider 12.4. On our Howell / EBL systems, we start at 13.8, but the system continues to go richer the longer you are under heavy load. I have seen it get down to the low 12s. The cruise and WOT AFRs are at 1100, 3000 and 6000 rpms. IIRC, I set all to the same number. Started and ran great without any hesitations, stumbles or coast / acceleration transition issues. I’m thinking that the self learning was having trouble getting everything sorted with starting values so much richer than what our engines require. Armand made changes to the accelerator pump parameters [I had to set all of the setting to +45] as well as decel open IAC [+10] parameters that helped but didn’t solve all the problems until he made the AFR changes I suggested above. Hopefully, this might help some who are installing the FiTech.

11/8/2016 – Making the log recorder work

If you want to record and retrieve a log file on the handheld then you must make sure the log directory is set up correctly – mine was not and the factory default file (see the first item in the note below) does not have it set up either. Plug the handheld into your computer via a standard usb cord, navigate to the log file folder and delete the “dashboard” folder. The handheld will then reinitialize that folder and record files in it.

11/8/2016 – This note was provided by Bob Miller who got it from Cody at FiTech:

Resetting to a stock calibration:
From the main menu go to the very bottom and select Write Cal To ECU.  Once in this menu scroll down to the second to last selection, it should say Default v8 T195. Once on this file select it and it will download to 100 percent. After this is done it will revert to the main menu. Now go to Go EFI Initial Setup, then Engine Setup, now input all of the parameters that are needed for your application, making sure to save each one individually. 

After you have entered your information and saved it go up and select Dash Board. Once in dashboard turn the ignition key off and wait for all the data to black out. Once this happens turn the ignition key to the on positon and start the car. 

IAC Steps:

Turn the driver’s side throttle adjustment screw IN (clockwise) half a turn to start with, with that done turn the key on and go to dashboard and find TPS and make sure it reads zero. If not, then shut the key off and wait for the numbers to go black then turn the key on again. Once that reads zero start the vehicle and find IAC Steps on dashboard. This number needs to be within 3-10 at warm idle. If the number reads zero then slowly turn the screw OUT (counter clockwise) until the IAC steps reads between 3-10. If the number is above 10 then shut the vehicle off and turn the screw IN as stated above and repeat the process until the IAC steps are between 3-10.

Reset Learn:

All Fitech EFI systems have learning procedures that the system uses to adjust the active fuel tables it is using for operation. Sometimes if there are outside problems such as bad misfires, exhaust leaks, or any other situation that could cause poor readings on the O2 sensor, the system will try to compensate in order to keep the car running. If this happens it alters the fuel map in ways that may not be optimal for proper running the engine normally.

To reset the learn is a very easy procedure. Go into the Go EFI Initial setup then find Reset Learn. Once in that menu find Reset All Learn, highlight this and push right on the joy stick to go to #1, then save that to the ECU by pressing IN on the joystick. Once that is saved go back to the main menu, and then up to Dashboard and select it. Once on dashboard turn the key off and wait for the numbers in the value side to go black. This mean the system has saved. You have now reset the learn function.

Cranking fuel adjustments:

With the key on go to the Go EFI Tuning menu, find Crank and Warm up. There you will see three cranking fuel selections. For cold starts add or subtract fuel from Crank fuel 65f, for hot starts add or subtract fuel from crank fuel 170f. Changing these settings should help with your start up issues along with setting the IAC. A good starting point is to change the settings in intervals of 10 to find which way you need to adjust the system to work better.

Accel pump/ Fast Accel adjustment:

If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. Then find Accel pump and press enter. You will see a menu with multiple different settings, you need to focus on the Accel pumps (20f, 65f, 170f) and Fast Accel (20f, 65f, 170f). These setting adjust how much fuel, at varying temperatures, the system injects when you accelerate. Accel pump is used for any normal throttle input, Fast Accel is for any fast throttle inputs or Wide Open Throttle.

Hesitation: If the vehicle has a hesitation (when you step on the throttle and the engine does hangs and/ or almost dies and then suddenly take off) this normally is a lack of fuel so you would fix this by increasing the Accel Pump (for normal throttle input hesitations) or Fast Accel (for fast throttle or WOT inputs). You would make changes starting in increments of 10, to the temp range that you are finding the issue to reside in. 

Bogging/engine loads up/slow to respond: If the vehicle is bogging (when you step on the throttle and the engine is slower/sluggish to come up to a higher rpm) this is normally caused by over fueling. To fix this you would need to reduce the amount of fuel it is injecting as an accel pump shot. To do this this decrease the Accel Pump (for normal throttle input hesitations) or Fast Accel (for fast throttle or WOT inputs). You would make changes starting in increments of 10, to the temp range that you are finding the issue to reside in.

Choosing a cam selection: 

Cam selection is based on vacuum load of the engine. Cam 1 is for 15Hg or above, Cam 2 is for 10Hg to 15hg, Cam 3 is 8Hg to 10Hg, Cam 4 is 8Hg to 6Hg. These are estimates and you may need to switch between them if the vacuum load is between two different cam settings to get the engine to run better for your application.

Idle Return:

If the engine is not returning to idle quick enough for your liking or is dropping too quickly and killing the engine then you may need to adjust the rate at which the injection system comes to an idle. To do so you need to go to Go EFI Tuning, then find and select Idle Control. Once in this menu you will see several settings, the only one we are going to work with is Decel open IAC. This number should be at zero as a base setting, by going negative you are reducing the amount of time it takes to return to Idle, and by going positive you are increasing the time it takes. Normal procedure of adjustment is to add or subtract 10 to start with and then adjust it to your liking or what the engine needs. Then once the setting is input save it to the ecu by pushing the joystick IN, the handheld will show Send To ECU Successful. Once this is done make sure to go back to the dashboard and turn the key off until the numbers clear out on the value side. This shows that the system has saved.

AFR Target Adjustment:

AFR: Air Fuel Ratio. Some vehicles may have greater needs for fueling that the self-learn may not be able to adjust in a great enough amount to operate correctly right out of the box. The injection unit is always trying to maintain a targeted AFR throughout its operation. It is either adding or taking away fuel at any given time from its current fuel table in order to do this. The AFR target is what the computer is constantly adjusting for (the higher the number the more lean the mixture, the lower the number the more rich the mixture is), but some engines need different fueling depending on the CID and cam they have. To adjust these numbers you must go to our Go EFI Tuning menu then to AFR targets, typically adjusting any AFR target should be done .01 at a time either up or down as the AFR has drastic effects on how the engine runs 

Once in this menu you will see 10 settings you can adjust. Number 1 is for Idle AFR which can range from 13.4 to 14.7 on average depending on the engine. Adjusting this setting will help idle quality and takeoff from an idle. The 1100, 3000, 6000 at 45kpa cruise are your cruising AFR ratios, these can vary from 13.8 to 14.7 on average depending on the engines needs and your desired fuel economy. The cruise AFR only effects cruise so it will not affect your acceleration or other AFR settings. WOT 1100, 3000, 6000 are your acceleration enrichment settings and are used for adjusting the desired fueling for accelerating under either part throttle or WOT. The average for these settings only ranges from 12.4 to 12.7, any accelerator needs beyond that will require one of our technicians to go over with you. Boost 1100, 3000, 6000 180kpa should stay within 11.5 to 11.7 on most engines with boost, any further adjustments to your boosted AFR settings should be brought up with one of our technicians.    

 

FiTech Fuel Injection with Fuel Command Center Installation

FiTech Fuel Injection with Fuel Command Center Installation

This post is actually a compilation of some emails I wrote to a couple of other GMCers while the process was going on. Sometimes things are repeated but I did try to update a subject each time I mentioned [updates in brackets like these] it but it might still seem a little scattered. Sorry.

When we went to the GMCSJ rally at Tombstone we got the opportunity to talk to Jerry Work and see his FiTech EFI system. I took photos of his Fuel Command Center mounted on the passenger side of the radiator and then shot some photos of the throttle body with views of linkage and hoses. Those photos and one of the underside of my engine hatch are just below:

 

The following are separate sections, divided by day, that describe my progress.

I ordered my FiTech system soon after the Tombstone rally but the Fuel Command Center was backordered until March 15th. They did send it on that day.

On March 23rd I wrote the following:
I got the Fuel Command Center installed right where Jerry installed his. I used 1″ aluminum angle  to attach the FiTech-supplied brackets to the radiator housing instead of the white plastic panel in the photo of Jerry’s. But, installing the Command Center is as far as I got before I had to install 130 feet of baseboard in a rental house and the visiting grandkids arrived. The kids just left this morning. I have to finish the baseboards in the rest of the house – another 150 – 200 feet – this week while hosting Carol’s Mom’s 90th birthday party on Thursday. After those things are done I hope to install the EFI and then drive it to the Marana Bluegrass event on 4/8-4/10 [didn’t make that date]. If I don’t make that I will have to fit it in with my son’s visit a few days later. I definitely will have it in so we can drive to the GMCWS rally in Temecula.

The instructions look pretty easy except for drilling a hole in the exhaust pipe although Jerry said that was a piece of cake [it was. Just jacked up the right front side a couple of inches and removed the fender liner]. The instructions say that you cannot run the engine with the O2 sensor installed and no EFI working – it will damage the sensor. I confirmed that with the FiTech people. That means, if I want to be able to drive it, I have to be sure everything else is ready before cutting the hole or I will have to install a plug instead of the sensor if still using the carb.

On April 3rd I wrote:
I have the fuel “Command Center” installed and have the vent and fuel supply hoses installed on it and in place on top of the engine. I have run the wires from the six-wire harness to the places they go but they are not soldered in yet. I have run the display cable up under the dash but not in place – they supply a suction-cup stand to hold the display but I don’t know if the cable is long enough to use it. [I since moved the cable so it enters in the center of the dash and it is long enough for that].
I removed the carb and tried fitting the TBI onto the manifold but it turns out the general purpose throttle connection lever sticks down below the level of the manifold. Jerry Work said he cut it off but didn’t say how – my only option is a grinder. I sent a message to FiTech asking for advice if any. [Their advice was to use a spacer – I cut it with a grinder].
I also will be needing an adapter plate of some kind. They suggest a Summit Racing (SUM-G1420) which is only 1/8″ thick while Jerry Work used a 1/2″ thick adapter he bought at NAPA and then had to modify his hatch to accommodate it. I had hoped to get away with just the thick gasket I had under the carb but now I will be ordering the adapter after I verify that 1/8″ will work. [It turns out that I needed 3 adapters stacked with 8 gaskets – 2 from FiTech and 6 from Summit].
Some hardware for connecting the throttle and cruise control cables is also needed. Jerry got his at NAPA so Merle’s should have it too [They did not but I did find them on Amazon]. The numbers Jerry gave me for this are Manifold to throttle body adapter – NAPA 735-4930 [this adapter was too tall for my coach], Carb linkage bushing 1/2 to 1/4” – Mr. Gasket 6026 from NAPA, Carb linkage 1/4” stud kit (bolts through bushing on throttle body linkage to accept stock GMC throttle cable) – Holley 20-38 from NAPA. [I used the stud kit but it was too short to use both sides of the linkage bushing so I just used the back of it with the stud.]
I put the carb back on and now plan to get the TBI installed the week of the 11th so I can drive it a little before going to the GMCWS rally three weeks later. [Didn’t make that date either].

On April 13th I wrote:
I finally got back to working on the FiTech installation yesterday (Tuesday) and immediately found out that the FiTech guy who told me that I didn’t need an adapter plate was wrong – it was not even close. I started calling around and found one at Autozone but it was too thick – with gaskets it would be almost an inch thick. I called Don’s Hot Rod and they had one that was the same thickness. I had the NAPA number from Jerry Work for the one he bought so I called them and they said they could have it by 8:00am today so I said go.

When I picked it up I thought it looked a little thick but drove home anyway. I tried it on the coach – Jerry used it so it must work – but it ended up being about 3/4″ thick. It is actually closer to 3/4″ thick than it is to 1/2″. I put it back in the package and ordered 3 of the Summit Racing 1/8″ spacers that FiTech says work. My measurement of the space required for the butterflies on the TB is 3/8″ so three of them should work. I did think of making my own but, other than wood, I don’t know what material I could use. [It turns out that 3 of the Summit adapters was not quite enough but the addition of 4 extra gaskets that are included with the adapter plates and FiTech kit did the trick.]
I drilled a hole in my exhaust pipe for the O2 sensor yesterday and found that the clamps that came with the unit were way too big for my 2 1/2″ exhaust – they were too big for any normal exhaust pipe so I had to buy two more at Ace HW.
I have everything connected and even have the Fuel Command Center primed and ready. I even used my router to give the air cleaner another 1/2″ of space. As soon as I get the spacer thing fixed I will be able to start it up. My son is coming for a visit this weekend – arriving Friday – so I will not get to work on it again until Tuesday. Stay tuned.
On April 20th I wrote:
I ordered 3 of the Summit Racing adapter plates (SUM-G1420) that are 1/8″ thick each. I installed all three of them with one supplied gasket between each metal-to-metal joint and it was not quite enough so I added 4 extra gaskets (2 from adapter plates and two from FiTech) at the top and that did it. That did raise the air cleaner enough that I had to route out the forward portion of the engine hatch by 1/2″ deep and had to give it an extra inch forward. I bought 4 – 5/16-18 1 3/4″ bolts and torqued them to the 16 pounds specified.
On Saturday I installed the throttle body and connected all of the plugs and it started right up and ran nice and smooth. My son was visiting so I decided that was enough “fun” for the day and I shut if off. I locked up and turned the engine battery off and then thought about the installation instructions saying that constant battery power is required. That is so that the unit will have time to record its self-learning data. I turned it back on and went inside to look at the controller and, sure enough, it had been reset. I also noticed that the controller was on without the ignition key being on. I was informed by FiTech that this is normal and the alternative is to disconnect the controller connections (easy to do).
Besides starting the engine I was really anxious to see how the air cleaner and hatch cover fit. I immediately found that installing the fuel inlet at the rear left corner was a mistake – the air cleaner was hitting the inlet fitting. It turns out that the air cleaner has more room at the left front with the inlet pointing just aft of the alternator as usual and that fits fine. I left fixing the air cleaner for Tuesday when my son was leaving.
On Tuesday morning, after my son left, I finished making connections (the fuel vapor cannister hose is 1/4″ and the vacuum inlet is 3/8″) and moving the fuel inlet fitting. Now I installed the air cleaner – the FiTech unit requires a 5/16″ stud to hold the air cleaner and the top of my air cleaner had to be drilled out a little to allow it to fit. I just used a hex nut on the top, hand tightened. This is when I found out the the air cleaner is forward of the center of the recess in the hatch by about 1/2″. I had to enlarge that area and it now fits – I had to push down a little but I think that is due to the new weather stripping I installed at the same time. If necessary, I have a plan to add more space without a big lump in the middle of the floor. I hope I don’t have to use it.
Another problem I have identified is my fuel pump. I have only an electric pump installed just in front of the tank selector valve. A while ago, my mechanic noticed that the pump would not always turn on when the engine was started. I diagnosed it to be caused by the oil pressure switch which is there to shut the pump off if there is no oil pressure – i.e. the engine is not running. Gunning the engine a little just after starting was required. I noticed on the first start on Saturday that the electric pump was not running – the Command Center low pressure gauge was at zero. Given that the Command Center is holding somewhere between 1 and 2 quarts of fuel, a failed electric pump would take a while to notice. I bought a new switch and it seems to be working better.
I took it for a test drive today and I am impressed. When I first started driving there was a pretty familiar hesitation when going from no throttle to partial throttle but by the time I drove the two miles home via some stops and turns it was almost gone – self learning in action I assume. I then drove it to the NAPA store in Marana (to return the carburetor adaptor that Jerry Work used – too thick for my coach) and by the time I got back it was running great. Also, I will have to watch my speed on the highway because it wants to go faster than it used to – I love it. Now if my “vapors” problem is gone it will be worth the effort and money.
I had to buy 4 new bolts to bolt the TBI unit down to the manifold. I think they need to be 1 1/2″.

Reworking the OEM Dash Air Conditioning System

Reworking the OEM Dash Air Conditioning System
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Under-dash air conditioner installed by a PO.

When we got our coach it had an under-dash air conditioner that some previous owner (PO) had installed in place of the original equipment (OEM) setup. The OEM system was never very good until the mid-1977 and 1978 models and even then I hear complaints. Our coach is a 1976 so the system was not good – it did not blow very much air and what it did blow was 100% from outside air so it was not very cool and gave hardly any heat in the winter.

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My solution to the ugliness and inconvenience of the PO-installed under dash unit

The under-dash unit was in the way, poorly installed, and made lots of noise from fans hitting housings, etc. I hated the way it looked and hated that it got in the way of the suspension switchs and of having a tray or other platform for holding drinks, food, and our navigation computer. A couple of years ago I made a cover for the under dash unit that made it a lot more attractive and incorporated a swiveling tray that held drinks, food and our computer.

Our last trip – the June 2015 trip to Northern California – was so hot and uncomfortable that I decided to do something about it before our next trip in September when it will still be hot here. I had read and heard that there were solutions to the problems with the OEM system. One fellow GMCer that I talked to last Spring at our Treasure Island rally said that he had to turn his down on the trip to the rally even though it was about 100 degrees out.

2015-08-22 07.47.33

This is showing the hole that I cut in the back of the input chamber of the HVAC box and the coach fire wall to allow inside air to be taken in instead of the hot outside air as designed. The damper control on the right is the “max air” damper that is now normally open unless the “defroster” cable is pulled. The spring helps keep it open.

Fixing the OEM system requires two things: converting the system so that all of the input air is recirculated from the already cooled (or heated) interior air – commonly called “recirculate” on controls. This involves cutting a hole in the back of the fan intake section of the system and through the firewall so inside air will be drawn in. Covering the outside air intake forces all (95% probably) air to come from inside the coach. The OEM control has a position on the temperature control that says “recirc” but it does not – that control is supposed to open a door that sends most of the cooled air inside so should be labeled “max air” if anything.  There is no recirculation in the original setup.

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This is a view of the hole in the fire wall from inside the coach. I used a hole saw, a 4 1/2″ grinder, and a reciprocating saw to make the hole. I protected the wires with blocks of wood while I was cutting. This hole is directly behind the glove box and next to the fuse box.

The second part of the requirement is to simplify the routing of the conditioned air – the standard ducting system is so convoluted that hardly any air comes out. I looked at our system and determined that the duct work and its controls were so old and leaky (it uses vacuum from the engine) that it was hopeless to get it working again. One of the vacuum actuators actually disintegrated in my hand when I touched it. Instead of using the ducting system I plan to just keep the “max air” door open all the time unless we need defrosters at which time I will close the “max air” door and allow air to go through the OEM ductwork but completely uncontrolled. I also plan to turn the heater valve on and off mechanically (instead of the non-functional vacuum system) and control the flap that regulates the amount of air flow over the heater core mechanically (like it was originally). The heater valve, the “max air” door, and the heater air flow damper will all be controlled using old-fashioned manual choke cables in place of the non-functioning vacuum actuators. The air conditioner will be turned on with a toggle switch and the fan will be controlled using the OEM switch and wiring.

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The modified OEM control panel has the original fan speed switch on the left with 4 controls on the right. The toggle switch controls the air conditioner clutch and when it is lit on the end. The first knob turns the heater valve on and off, the second controls the heat damper, and the third closes the max air vent damper and forces the air through the duct work and maybe some defrosting.

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The back side of the OEM metal control panel – the extra washer is because there was a high spot on the other side of that control that needed to be offset

Since I needed to hold the original fan speed switch, a toggle switch for the air conditioner, and three “choke” cables I decided to just modify the OEM control panel.  The front of the control panel is made of cast metal with a plexiglass insert. The back of it has standoffs to hold the fan speed switch. I removed the plexiglass insert and used a grinder to flatten out the face of the metal part so that I could replace their plexiglass insert with my own.  In the original arrangement of controls the right side of the panel had two left-to-right slide levers that selected mode and temperature. I drilled holes in the slot that housed the top slider and backed them with washers to hold the new controls. I made my insert from a 1/8″ plexiglass scrap, printed clear labels with mirror imaged text that I installed behind the plexiglass and then painted the back of the plexiglass to hide the ground-down metal panel behind it.

The cable that controls the heater on/off valve and the one that controls the damper that controls air flow over the heater core were no problem but the “defroster” cable, the one on the right, is a problem. My idea was that under normal conditions the “max cool” opening under the dash would be wide open and when we needed the defroster function I could close that damper and force the air through the old vent system and then some of it would be directed on the windshield. I had a real hard time getting the cable positioned correctly to perform the function because of the position of the control lever and the directions it had to move in.

Below are some detail photos and the finished product. I can report that the dash air conditioning is now performing the way you would expect a good dash-air system to work – it blows lots of cold air. Success!

2015-08-22 08.17.46

The “max air” vent exits the HVAC box in this approximately 2″ x 12″ hole under the dash and pretty close to the new intake hole. The damper that is supposed to open with “max air” is right beyond this hole. Originally, there was duct work that directed this air toward each side of the cockpit. The cable that is crossing the opening is the “defroster” control cable making its way from the dash panel to the HVAC box – it was slightly repositioned later to avoid conflict with the duct work.

2015-08-22 08.19.12

This shows the duct work that I got from Golby in Florida in place and waiting for the diffusers that Golby also supplied. The wooden piece attached to the dash is the console pivot point holder.

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This is the new center console arrangement. The triangular gizmo holds it up and provides side-to-side stability while allowing it to be positioned where we want it. Moving it just involves lifting and sliding side to side. Removing and storing it is easy too.

2015-09-10 12.49.26

This view shows the “finished” product. I cut a hole in the glove box to allow the return air to flow more easily. I installed the diffusers in the max air duct and they really help direct and focus the cold(!) air.

 

Painting my GMC motorhome

Painting my GMC motorhome

I spent lots of time and effort between January 2014 and the end of July 2014 doing body work and painting the GMC. While I was preparing for the trip to the Fall 2014 GMC Western States Motorhome Club rally in Manteca, CA I was asked to do a seminar at the rally. Preparing the seminar I did the following write-up first and then made the slide presentation from it. The slide presentation is available at the bottom of this post.

Color selection and design:

IMG_4342We have had our Classic GMC Motorhome for almost 8 years and for all of that time a paint job was very high on our list of desired improvements. We tried buffing the original Imron paint but there had been repairs that were not Imron. The stripes were painted on top of the Imron and were well worn in addition to being very 1970s – the orange stripe was the biggest clue for dating it.

2013-09-14 12.31.07We made many improvements: mechanical, convenience and cosmetic. In 2010 we remodeled the entire interior – all new cabinets and window coverings but we never got around to the paint job. In 2014, the paint job finally made its way to the top of the “desired improvements” list so it was time to do something about it.

bluocityOver the eight years and multiple rallies at both GMC Motorhomes International and GMC Western States, along with lots of photos from rallies we could not attend we developed an idea of what we wanted for a paint design. The dream paint-job was based on a design that I saw on Jim Bounds’ web site – he calls the coach Blueocity. Blueocity’s base color is a bluish gray with black around the windows. Our dream job had a base color of beige (no specific shade but) close or similar to the original base color to keep it light and compatible with our interior colors.

When I went out looking for a shop that would do the job (more on that below) I was told that changing the design from the original would cost quite a bit more because of all of the sanding required to hide the old stripes. Rethinking the design, we came up with the possibility of repainting the same design with new colors. At that point I contacted Byron Songer, the design and graphic arts guru. Before Byron did anything, however, we changed our minds (I decided to do the paint job myself – more below again) and went back to our original plan.

When I finally went to the paint supplier I found out about a complicating factor that might have forced us to abandon any Byron Songer solution anyway: automotive paint colors are “a crap shoot”. It turns out that available automotive paint colors, for the most part, are determined by automotive manufacturers. The color choosing process is to look at thick books of paint colors with small (about 1” square) swatches of available paint colors in no obvious order – they seem to be in order by manufacturer and model year. There are no meaningful color names, only numbers, and no available range of a color as there is in home décor type paint store. This would make painting the original colors easy but not great for design.

Hire someone or do it myself?:

My original plan was to find someone to do the paint job for me but I ended up doing it myself. I had toyed with the idea of painting the coach myself because it was interesting – I love learning how to do things. Also, I knew two people who had done it themselves in their driveways and both coaches looked fine – no evidence that they were done by amateurs.

Trying to find someone, I researched and thought about the tried and true Jim Bounds Coop in Orlando, FL and Topeka Graphics in Indiana. I knew (Steve Ferguson and Jim Decheine) that Jim Bounds did great (the best) work but I had heard that the price was quite high – $10K – $12K plus the trip to Florida (leaving it there would require two trips adding quite a bit to the already high cost). I thought of Topeka Graphics because they had done several GMCs for others and the quality was good and the price seemed right at the time – about $5K. When I called them about a year ahead of time they had stopped painting coaches and gone back to their prime work of doing graphics on big RVs.

Now I started searching around the Tucson and Phoenix areas. I called shops which seemed to be likely to be able to do the job but was unable to find anyone who would do it. I asked people who had coaches painted and only two shops were identified. One of the people who stores their non-GMC RV where I do had theirs done at a shop in Tucson. When I visited the shop and showed them the coach they were very negative and, although cheap, were going to do a bare-minimum job if they did it at all. Also, they did not have a facility so would have to do it outside.

I ran into the owner of a very large diesel pusher at a Jetset rally who had just had his coach painted at a place in Tucson that does RVs for one of the local dealers. He had paid only about $8,000 and it was huge so I went to see them. They had the facilities and the knowledge but, if I did much of the grunt work (removing and reinstalling all of the lights, etc.) and gave them the coach for at least 2 months, they would (no body work since I had already done most of it) paint the coach for only $9,000. That is when I realized that Jim Bounds’ price was pretty fair and also when I decided to do it myself. I figured that if I could finish with a “10-foot” paint job I would be happy and would equal some of the paint jobs I have seen done in “Mexico” or elsewhere (cheap). A “10-foot” paint job means: from 10 feet away it looks great.

What was required to do it myself?

Skill requirements:

Doing the paint job myself seemed like an exciting and rewarding project. I had sprayed paint before when I made cabinets and furniture and I knew others (Steve A., Karen B., and Sully) who had painted their own coaches themselves at home, in the driveway. If they could, so could I.

It turned out that there are hundreds of free videos on youtube.com that teach everything you need to know about body work and painting. I watched many hours of video trying to learn what I needed to do the job.

Youtube:

  • DIY How To Paint A Car School
  • diyautoschool
  • Eastwood Company (Kevin’s Corner with Kevin Tetz)
  • Official How To Paint A Car – DIY Learn Auto Body And Paint
  • Refinish Network

Tool requirements:

earlexThe biggest hitch seemed to be an air compressor to run the spray gun and the sanders. I had a small air compressor but everything I read talked about how you need a lot of air and the only way to get the amount they suggested was to use a huge 220-volt air compressor that would cost at least $500 but more like $1000 or more. Well, the truth turns out to be that the reason body shops use spray guns that require lots of air is that they have lots of air. Body shops have air tools like sanders, chisels, hammers, etc. that have always taken lots of air. HVLP spray guns – the state of the art tools – do not require pressure, just lots of volume. HVLP guns, as originally developed, are driven by turbines that move lots of air at low pressures – like the exhaust side of a vacuum cleaner.

Turbine system Benefits:

1) Complete Portability typically 20 lbs.

2) Built in filter system

3) All Self contained

4) Fast operation with heated material (I needed something to slow it down)

4) Excellent finish quality

5) Very Low Overspray – Great for indoor applications

6) No moisture to worry about

Other electric or air tools required: 4 ½” angle grinder/sander for body work, a 5” random orbit sander, and a 1/4-sheet finishing sander from Makita (easy to use and very aggressive).

Where to work?

2014-07-03 09.07.04I am not allowed to park the GMC at my house so either renting a space somewhere, indoors or out, or doing it right where it was stored were my only options. There were no opportunities I could find for renting space indoors so I decided, with the approval of the storage lot owner, to paint the coach right where it was parked. There were two fairly trashed cars on one side that belonged to Ed, the storage lot owner and a white class C Motorhome on the other. There was less than 8 feet between each of the spaces so overspray was a big concern for me.

The turbine-based HVLP spray system turned out to be a life-saver again. The first section I painted was below the waist on the side nearest the cars and there was almost no overspray. I had planned to turn the coach around so that I was painting on the car side again – Ed “didn’t care” about the cars’ paint jobs – but I decided that there was no risk just leaving it right where it was. The only time I did move the coach was when I painted the roof. I worried about paint going over the top and onto the Motorhome on the other side so I moved out into an open parking lot in the storage facility.

2014-05-22 17.43.28Speaking of painting the roof: how to reach it was the biggest problem I had with the work area. I don’t know how real shops paint the roofs of GMCs. I think I remember even Jim Bounds saying that they send coaches out somewhere to have the roofs painted. I did see a situation where someone painted theirs in a barn where they could walk on platforms or planks suspended above the vehicle. I ended up using an 8-foot stepladder leaning on the side of the coach and had to move it 3 or 4 feet at a time but reaching the front was a real problem that I might do differently next time – if I could think of anything that I couldn’t this time.

Other than some dust and a few bugs in the finished paint job painting the coach out in the weather on a gravel lot in the Arizona Summer sun worked out OK. I did all of the painting as early as there was light enough to start – usually 5:00 to 5:30 a.m.

Painting the coach

Preparation:

There are basically two ways to paint a vehicle: “bag and shoot” or “the right way”. Jim Bounds and the GMC Coop in Orlando, FL is the “gold standard” for painting the GMC. “Bag and shoot” is what Jim calls the typical cheap paint job. Everything that can be masked is masked, little or nothing that is not to be painted is removed. The right way to paint a vehicle is to remove everything that can be removed so that nothing gets painted that shouldn’t be and so that the surrounding areas can be properly cleaned and prepped. Another benefit is that when the item is removed and replaced there is no problem with a change in shape and old paint showing as a result.

IMG_0454I took the path of removing everything. The only things that I did not remove are the vent fans on the roof but I did remove the caulking and clean the areas around them. The air conditioners – two of them – were too heavy for me to completely remove so I built 14-inch by 14-inch frames out of 2x4s on their edges. The frames move the base of the A/C unit 3 ½ inches above the roof – enough to get paint underneath and do the job.

One of the biggest questions that I had and I see others discussing on the web was whether or not to remove the drip rails (the rain gutters that cover the seams between the roof and the sides). I asked Jim about this and he told me that they always do and that, although it is a big job, it was the “correct” thing to do – I removed mine and I am glad I did. One rail, on the passenger side, came off with no problems – probably because someone had been their before me some years earlier. The driver’s side was a different story. About every other screw broke off in the structural rib. Jim had predicted this and said just move it forward about ¼” and drill all new holes when reinstalling.

90410A245The replacement of the driver’s side rail required me to grind the old broken screws down flush with the aluminum. I used a 4 ½” grinder with a metal cutting wheel on it to reach into the groove where the screws go in. I bought some self-tapping screws from McMaster-Carr and used a slightly oversized drill bit (11/64) for drilling the new holes and I had no problems getting the new screws in and tight.IMG_0766

I used 11/64″ drill bits, specifically:  DEWALT DW1211 11/64-Inch Cobalt Split Point Twist Drill Bit.

I did remove the front “hood” doors and the fuel, hookup, and water-fill doors for sanding and repair but I reinstalled them before painting so that the hinges, rivets and screws would be painted.

Body Work:

SMC: the end caps and the body below the waist are made from SMC which is pretty much like fiberglass. The SMC panels are glued to the aluminum body structure. SMC contains a mold-release agent that is embedded in the material and must be wiped off  with a solvent before repairing. The materials are different than for regular fiberglass and are specifically labeled for use on SMC – and they cost more.

97447A210The roof and the sides above the waist are made from 16 gauge aluminum sheet that is glued and/or riveted to an aluminum body structure. Significant aluminum repair requires a lot of skill (that I don’t have) but, fortunately, I only needed to repair a bunch of small screw holes and a couple of antenna holes – about 1” or 2”. Knowing that no one except me and the next owner would ever see the roof close up I didn’t worry about the antenna holes too much. I riveted pieces of aluminum roof flashing under the two larger holes and then covered them with a body filler made for bare metal – you cannot tell (yet). All of the screw holes in the aluminum were countersunk and filled with a countersunk aluminum pop-rivet (McMaster-Carr #97447A210) and then covered with the body filler – quick and easy.

2014-09-11 09.07.15The only other significant work revolved around removing an accumulation of silicone sealer from a few areas. I used a commercial silicone remover, a putty knife, and a wire brush to get the silicone out of the seams. Nothing sticks to silicone so it has to be removed completely.

Cleaning:

Cleaner used before and after sanding - removes grease and siliconeThe old surfaces should be cleaned before any more preparation is done. Special attention should be paid to making sure all silicone sealer has been removed before sanding because sanding can spread the silicone. On the heavy silicone deposits on body seams and lots of other places I used Motsenbocker’s silicone remover and I used “Prep-All” from my autobody and paint supplier everywhere – it took off what the silicone remover left.

Masking:

Windows and window frames, bumper brackets and frame, A/C units, and anything else that you cannot get off must be masked. If you are going to mask something and then get it painted quickly you can use cheap tape and paper. If you are going to leave the masking tape on for any length of time (more than a day or two) you should use “good” tape (I used 3M 233+) since it is supposed to be easy to remove without leaving any adhesive behind. If you are painting outdoors then all bets are off. Rain will soften cheap tape and shrink paper. The sun will cause even the good tape to leave adhesive behind after just a day but the good thing is the good tape is very resistant to water.

I masked my coach several times over the course of the project and I found that the best idea was to mask with plastic sheeting (3.5 mil) and “good” tape. This masking can make it through rain and wind with few issues. Since my masking stayed on for several days at a time the tape did leave a lot of residue, particularly on rubber around the windshield and the rear window.  Even 3M Adhesive Remover would not touch it but it did come off pretty well with lacquer thinner. Just remember that lacquer thinner removes fresh paint very easily.

Selecting the Paint:

If you were painting a coach indoors in a proper spray booth the whole process could probably be completed in one day – a long day, but still one day. Painting outdoors without the benefit of shelter from the wind and weather changes the picture quite a bit.

One of the things that complicate painting over a multiple-day period is the requirement of some paint “system” components that they be covered by the next component within a certain amount of time. A 2K urethane primer can be applied with no requirement that it be covered within any timeframe but a 2K sealer must be covered the same day. Etch primer must be covered with a primer or sealer within 8 hours. The base-coat (color) of a base-coat/clear-coat system must be covered within 24 hours with either another coat of base-coat or the clear-coat.

I started by trying to understand the choices of paint types: paint products are either “single-stage” or “2K”  (two-part) and the state of the art is “base-coat/clear-coat” (BC/CC) systems where the color is applied first and then covered with a coat of clear material that has the shine (or lack of shine). A benefit of the BC/CC system is that drips, sags, and orange peel can be “color-sanded” and then buffed very easily to remove the problem. I was strongly encouraged to use that system so I did not worry about the cost: the total cost for 3 different primers, 2 base coat colors, and clear coat was about $1,000. I did not price the cheaper paint.

The next consideration was color. For the main body we wanted to stay with a light color that was close to the original “cream beige” but was a little more lively. When I went to the local Finish Master store in Tucson I found that picking the color was going to be a little more difficult than I am used to for home decorating colors. Automobile manufacturers invent new colors every year. Each of the new colors is unique and has no complimentary colors – like you would expect for home decorating. If you want a different shade of the same color you are out of luck. Because I was planning to use the Blueocity scheme with only black around the windows I was not worried about more than one color choice but trying to paint 4 different stripes of the original paint scheme with a new set of colors would have been a nightmare.

Phase I – Painting the Bottom of Each Side

IMG_0098When I started the project I started with repairing the damage from several tire separations, multiple furnace installations, excessive bolt holes for fender liners and more. I repaired most of the damage and then primed the repairs with a primer that I thought approximated (“close enough”) the color of the original beige paint. My wife did not agree and I was required to get started on the paint job and to not go to the Spring 2014 GMCWS rally unless the primer was covered. The plan was to paint the sides – all of the panels that enclosed wheel wells and everything between them – with the new beige. I planned to paint the aluminum strip that covers the seam between the upper aluminum and lower SMC panels but stop there until after the rally.

I now had to choose a primer – I needed to prime at least the areas that had fresh body work done on them but I was told that the job would look a lot more uniform if I primed the whole thing. I had to use a primer that I could leave uncovered for multiple days because I could only work for 3 or 4 hours at a time and the primer had to be sanded before covering. I was limited to a 2K primer/surfacer –other primers must be fresh when the base coat was applied. The very thick 2K primer did not apply very well with my turbine-driven spray system. I don’t know if a better (more expensive) turbine system would have worked better but I am pretty sure it would have. The problem was orange-peel and it had to be sanded smooth – I got most of it smooth but not all. At least it is uniform 😉

After all of the body work one each of the lower sides was done I applied the primer and then the next few days I sanded out most of the orange peel. I then applied two coats of the (color) base-coat (a little too thin in a spot or two) and then two coats of the clear coat. It mostly came out pretty good although there were areas that needed to be sanded and buffed (this is normal) and one panel that needed to be repainted.

When I was spraying the base coat a dried up blob of paint from the gun stuck to the area right above the passenger side rear wheel well. I didn’t see it until after I had applied the clear coat. When I tried to sand away the bumps from this the next day, I discovered that I had damaged the base coat and that I would have to reapply it to hide the sanding. I “scuffed” and sanded the panel that goes over the rear wheels with everything else between the seams and above the waist line masked. I reapplied the color and then the clear coat. The result was a slightly different color. It turns out that this is common, the color is affected by the temperature and humidity when you are applying the paint.

We went to the rally and hardly anyone noticed the lower sides had been repainted but we did notice that people were much more interested in looking at our coach than they usually are at rallies.

Phase II – Painting the Roof

2014-05-22 17.43.28When we returned from the rally it was time to get down to business. The first order of business was the roof – where you sould normally start with a paint job. The roof is made up of three sections: the front cap that covers the cockpit and made of SMC, the main part of the roof made from a single sheet of 16 gauge (I think) aluminum, and the rear cap which is also made of SMC. The front and rear caps were in good shape with only sanding required, the aluminum section of the roof had a lot of small screw holes and their repair resulted in a lot of bare metal on the roof. Bare metal has to be coated with an etching primer and then sealed with a sealer or primer before painting. Also, the etching primer must be covered within 8 hours of application.

I had already figured out that using 2K primer resulted in a lot of extra sanding and I didn’t think that it would be worth the effort to make the roof look good – except on the side where you can see the first foot or so from the ground. Evaluating my alternatives resulted in selection of a 2K sealer rather than a primer to cover the etching primer. The sealer has to be covered on the same day as it is applied meaning the color and the clear coats would have to be applied the same day too. Everything had to be done on the same day. Painting the roof began at 5:00 a.m. with the etching primer. That was covered with two plus coats of 2K sealer, two plus coats of the color base coat, and two plus coats of clear coat. A total of 7 plus coats, all applied from an 8-foot step ladder that leaned on the sides and rear and hardly worked at all on the front cap – too far a reach. I finally finished at around 10:00 a.m. I estimated that I climbed that ladder 3 or 4 steps each time, at least 120 and maybe as many as 160 times that morning.

The roof came out pretty bad with dust, dirt, runs and sags but no one can see it – just me and the next owner.

Phase III – Painting the Rest of the Coach

IMG_20140707_072325_554 IMG_20140706_094319_310 IMG_20140706_081931_232So far, I had managed to live with the time requirements of the paint system but now I had a problem: painting the rest of the coach involved two colors and that required masking and more work than normal between base coat and clear coat. I could not get the rest of the work done in one day. What remained had to be done in five steps: 1) paint the black around the windows allowing extra paint to make sure everything is covered; 2) mask off the black that I want to keep; 3) paint the beige color; 4) remove the masking over the black; and 5) apply clear coat to the whole area.

Complicating the problem was the masking between color coats. The masking of the black could not be allowed to stay adhered through a hot summer day in Southern Arizona – it would either pull the paint off or leave adhesive behind. In order to get around the sticky tape problem I needed to paint the black in the morning and then mask it in the evening when it was cooler. Applying the second color in the morning and then removing the masking over the black should avoid the tape in the sun issue but what about the requirement to cover the base coat with clear within 24 hours? Applying the clear coat the next day meant that the black would be 48 hours old and the beige would be 24.

The solution is known as “inter-coat clear” and it was really hard to find out about, probably because most shops would do the whole job in a day and not have this problem so almost nobody talked about it. The specification sheets for the base coats say that they can be recoated at any time with another coat of base coat. It turns out that base coat is made up of a clear carrier material with color added. The carrier material is sold as-is and can be applied over previously applied base coats to “refresh” them. Dupont (and their Nason brand) calls theirs “222S Mid-Coat Adhesion Promoter”. Just apply a coat of this acting as if it is another coat of clear-coat and then apply your clear coat. Times between coats of these paints are very short – no more that 15 or 20 minutes.

I applied the black on one morning, then I masked it in the evening, painted the beige the next morning, then applied the clear coat the third morning. The masking did pull some of the black off and I ended up doing repairs: first black, then beige, then black, then beige, etc. for a couple of hours on the second morning before I was happy with the results. I applied the “inter-coat clear” and the clear coat on the third morning.

Color Sanding:

IMG_0565The great thing about base-coat/clear-coat systems is that they are very forgiving. Orange peel, drips and sags can be sanded out and then buffed to an even better shine than a good clear coat has. The process begins with a very firm or hard sanding block and 1200-grit wet/dry sand paper applied gently the next day. I saw a couple of different techniques on various youtube.com videos but the one that worked best for me was plain water applied generously from a spray bottle to keep the paper lubricated and checking progress by using a rubber squeegee to dry the area quickly so I could see reflected light in it. Once the problem is gone, go over the area with 2000-grit paper and then polish with a buffer and rubbing compound on low speed (you will burn the paint off with too much speed/heat). The biggest problem is residue of the compound in adjacent seams.

Plastic GMC logos:

IMG_0566IMG_0568I wanted the coach logo badges to be as close to original as possible so I made new ones. I made molds from the original logos, cast exact replicas of them, and then painted them black and clear coated them.
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Summary:

I am glad that I did it but I would not do it again without a proper place to work – at least an enclosed area. I estimate that I spent a total of 200 to 300 hours and, counting all materials, supplies, nuts and bolts, trim, etc. about $2,500. I could have probably saved a few hundred on cheaper paint materials and I already had the sprayer, sanders, grinder and polisher.

It would have been a lot harder without Jim Bounds’ help and advice.

I started out looking for a “10-foot” paint job, I probably have about a “5-foot” paint job and that is what I would probably expect from a local body shop for a minimum of about $5,000. I think that a cheap “bag and shoot” paint job probably suffers from more than visible preparation problems and will probably have some adhesion issues before too long.

I think a quality paint job – good preparation and expensive materials – will cost somewhere upwards of $10,000 with minimum body work required. Add more for repairs, trim, and various nuts and bolts and you are up to at least $12,000. I would expect that paint job to be at least a “5-footer” though.

Below is the slide presentation of this write-up that I did for the GMCWS rally in October 2014:

http://minniebiz.com/gmcmotorhome/wp-content/uploads/2014/11/Painting-My-GMC.pdf

Rebuilding the Onan carburetor

Rebuilding the Onan carburetor

Just as I was getting into the paint job after returning from our Spring rally trip to Hemet I used the Onan and it died. It coughed and ran rough for a few seconds and died. It would not start. I verified that I had spark and that the fuel pump was working so it had to be the carburetor. I figured I could take it off and clean it and maybe even rebuild it when the paint job was done. That was in April. It is now August and the paint job is done so, last week, I got started.

The first thing I did was take the carburetor off and, using the diagrams in the maintenance manual, disassemble it and see what was up. There was no obvious dirt anywhere but I did find that the float level was way off of the recommended settings. Since there was no obvious reason for the failure I decided the best path would be to rebuild it (new valve seats, etc.) and then adjust it. While I was tied up with the paint job I read of at least one person having trouble figuring out what was and was not included in the rebuild kit. I ordered the kit from Applied GMC and when I got it and read the included instructions and diagrams I saw the problem. The 6K Onan carburetor is not like any of the versions shown in the diagrams. There seemed to be too many parts – a spring that seemed to be extra and a couple of pieces ( an O-ring and a small gasket) that I could not find in my carb.

I laid out all of the parts that came in the kit along with the main needle valve and float valve seat from my carb, assigned numbers to each item, and tried to figure out what was what. I called JimK and asked him for help. Jim referred me to Greg, his carburetor rebuilder, who uses the same kit as I have.  Greg was kind enough to help me validate my guesses and to figure out how to go about the process. The results of our conversation are documented with the photo below (click on the photo to enlarge it):

1. Internal gasket at bottom of bowl – reuse the external gasket.
2. Intake manifold
3. Bowl gasket – if the old one is good reuse it.
4. Spring – not used
5. Idle adjustment needle – use the spring from the old one
6. Float valve needle
7. Float pin
8. Gasket – not used
9. Old main adjustment needle – with old O-ring still in place
10. Float valve seat with rubber seat still installed – see additional photo below
11. Gasket for float valve seat – see additional photo below
12. O-ring that goes on main adjustment needle (#9)
13. New rubber valve seat and retaining ring for float valve seat (#10)

IMG_0742

Back of float valve seat showing rubber seat at the bottom and gasket around top.

 

This shows the view from the back/top of the float valve seat. The gasket (#11) goes around the outside and the new rubber seat and retaining ring (#13) are pressed into it using a drill bit that just fits after pressing out the old one from the back with a smaller drill bit.

 

 

 

 

 

 

 

 

IMG_0738

I thought I messed up

The instructions that come with the kit say to not touch the “nozzle” and that if you do touch it you need to install a new one. In a moment of confusion I did touch it but, it turns out, did no damage. It is reinstalled by turning until it bottoms – no problem.

 

 

 

 

 

 

 

After I had the information from Greg it only took me a few minutes to install the pieces and adjust the float – Greg does set the upper limit at 1/8″ (measured with a drill bit) and the lower at 5/16″ (estimated). The adjustments are made by bending – very gently with needle-nosed pliers, not by pushing on the float – a couple of tabs on the float. It took a few tries but I got it right. Greg says to adjust the 1/8″ favoring larger rather than smaller.

After reassembling the carburetor I installed it and the Onan started right up and ran great. I did not have to readjust anything although I verified that by trying. I think I’ll install the solid-state ignition kit by Gary Bovee next.

Body work – time to repair some SMC

Body work – time to repair some SMC

The classic GMC motorhome body is made up of aluminum and fiberglass-like material called SMC (Sheet Moulded Compound). The front and rear “caps” of the motorhome and the sides below the “waist” and made of SMC. SMC, like fiberglass, is somewhat brittle and when tires come apart, like they occasionally do on motorhomes, the SMC cracks and breaks when it is hit by the disintegrating tire. “Barbie” had some damage from a tire failure when we bought it – Uncle Dave had the right-rear tire come apart and make a hole in the propane door and the fender just in front of it. Since then we have had two more instances of tire failures – one on the same wheel as Uncle Dave’s and another on the middle wheel on the driver’s side. The driver’s side one did more damage there.

This post is going to cover the repair of the propane door. I intend to take some more photos of the fender just in front of the propane door when I begin that repair next week. I worked a little with fiberglass when I was a starving student in Omaha and had to repair a badly rusted VW bus but I really didn’t know much about it. I read all I could from the various GMCnet sources, I watched a few youtube videos and went to Finishmaster, our local auto-body supplier for some advice. They sell the Evercoat line of products for SMC and, after 3 trips, one for each phase of the repair, I have a nicely repaired propane door. Total material costs so far are about $210 for the supplies which should be enough to fix all the holes in the SMC – I hope.

 

 2013-09-14 12.31.30  This is the way the propane door and the fender just in front of it looked when we bought the coach. The tire had come apart on Uncle Dave and done this damage.
2013-09-14 12.31.07  Closeup of the damage.
 2014-01-29 09.46.22  Once I had the door off I found that there was more damage than previously visible. The rear corner and latch was almost completely broken off. Things I saw on youtube suggested using a grinder and opening up serious cracks and breaks so I did. I used some scraps of Formica-type material as backing, bent them using a heat gun and then glued them into place using the epoxy resin for the SMC.
 2014-01-29 09.47.14  This is a view of the back side of the repairs showing the plastic backing that was epoxied into place and shaped using heat. The curve was made to match the fender-repair piece (next phase of the repair) that Fay Curtis supplies.
 2014-01-29 09.47.39  A closer-up photo of the back of the repair.
 2014-01-29 09.47.48  Support for the “crack” at the rear of the door. It also was epoxied into place.
 2014-01-29 14.46.35  This is after the first “layup” of epoxy resin and glass fabric was put over the “crack” at the rear of the door and supported by the Formica backing. I think that this was 2 or 3 layers of thick glass matting and resin.
 2014-01-29 14.46.42  This is after the first “layup” of epoxy resin and glass fabric was put over the big hole and sanded off. This was after 2 – 4 layers of thick glass matting and resin.
 IMG_0005  This is the second layup on the crack at the rear of the door. The objective here is to bring the area up to near the finished level
 IMG_0006  This is the second layup on the missing section. Also trying to bring this up to the finished level – another 2 to 3 layers, more in one spot.
 IMG_0008  This is the SMC resin that I have seen recommended on the internet and by my local supplier. The little white tube is the hardener – a very small percentage is used in the mix.
 IMG_0035  There were a couple of small cracks developing around the vent louvers so I decided by reinforce the frame around them in the back. In the front, I opened up two cracks with a sander so I could use some filler on them.
 IMG_0038  This is the next coat as recommended by the Evercoat company and by my local supplier. It can be used as an adhesive or filler. It sets up fast even in (Arizona) cool weather but does a great job of filling. It took two or three thin layers to get the low spots filled.
 IMG_0039  This is the door after the filler was applied the last time.
 IMG_0040  This is the door after sanding the filler for the final time.
 IMG_20140131_105444_310  I used a Forstner bit to re-open the holes for the latches. I ordered a set of stainless steel latches from Applied GMC.
 IMG_0047  I bought a can of beige SEM primer and gave the “finished” door a light coat and was shocked to see lots of little pin holes and minor defects show up that I could not see before. Another visit to the supplier resulted in the purchase of this glaze that fills those minor defects. I was told that this was the normal process – it takes a coat of primer to see what you have missed.
 IMG_0047 cropped  Here is a closeup so you can read the label.
 IMG_0048  Here is the final product, ready for reinstallation.
 IMG_0049  This is the fender repair piece that Fay Curtis makes. I used it as a guide to match the curve for the missing piece. The next phase of the project is to install that fender repair piece.

List of all (or most anyway) repairs and upgrades to our ’76 Eleganza II

List of all (or most anyway) repairs and upgrades to our ’76 Eleganza II
Date Vendor Description Cost Mileage Owner
01/24/94 Southland Enterprises Buford, GA radiator, transmission & oil cooler lines, transducer, alternator 46661 Jim Bowles
02/25/94 Southland Enterprises Buford, GA fan clutch, transmission governor, exhaust system 46994 Jim Bowles
06/09/94 Southland Enterprises Buford, GA master cylinder, fuel lines 49694 Jim Bowles
08/30/94 Southland Enterprises Buford, GA RH cv joint & boot 51818 Jim Bowles
09/26/94 Southland Enterprises Buford, GA LH wheel bearing, knuckle and lower ball joint 52034 Jim Bowles
05/12/95 Camping World Heat strip for Duotherm Howard Black
01/10/97 fuel hoses
02/04/97 NAPA CV Joint boot 2456SB
03/19/97 Sams Club tires 60203 Jack Benson
04/01/97 NAPA Steering boot kit UVB101 13.00
04/17/97 Clasco Manufacturing Corp Front end – steering column master bearing, drag link, idler arm, tie rod ends and adjusters, relay lever, upper control bushings, lower arm control bushings, upper and lower ball joints 2,500.00 Jack Benson
06/26/97 Camping World Aqua Magic toilet
08/03/97 CarQuest alternator 156.00
03/24/98 Golby Motor Corp Front and rear brake hoses 181.00 Jack Benson
04/01/98 steering column bushings and bearing
04/24/98 Camping World Dometic RM2652 2-door refrigerator 949.00
07/10/00 Golby Motor Corp 9# radiator cap 10.00
08/21/00 Golby Motor Corp Air bags (2) 530.00 75890 Jack Benson
05/17/02 NAPA heater blower motor relay Patrick Loe
05/22/02 Alex Sirum GMC headlight kit 225.00 Patrick Loe
05/31/02 Golby Motor Corp Grille, door latch, holding tank sender 438.00 Patrick Loe
06/17/02 Alex Sirum GMC water tank sender 121.00 Patrick Loe
07/17/02 Ramco Ramco mirrors 411.00 Patrick Loe
09/16/02 Alex Sirum GMC Install complete macerator system 300.00 78906 Patrick Loe
09/16/02 Alex Sirum GMC complete front brake upgrade – new rotors, 80mm calipers, hoses, carbon metallic pads 531.50 78906 Patrick Loe
09/16/02 Alex Sirum GMC replace both windshields 1,050.00 78906 Patrick Loe
09/17/02 Alex Sirum GMC Trailer hitch – thru bumper 250.00 78906 Patrick Loe
09/17/02 Alex Sirum GMC 3.55 final drive 1,250.00 78906 Patrick Loe
09/17/02 Alex Sirum GMC rear brakes, new Delco shoes, new o/s cylinders 206.00 78906 Patrick Loe
09/17/02 Alex Sirum GMC KYB shock absorbers (6) 297.00 78906 Patrick Loe
11/20/06 Uncle Dave original purchase 10,000.00 81041 Armand & Carol Minnie
11/27/06 Simonson Generator tune up Onan generator 322.48 Armand & Carol Minnie
02/13/07 B&B auto repair fix leaking radiator 477.49 Armand & Carol Minnie
03/06/07 Cinnabar Propane tank sender 52.84 Armand & Carol Minnie
03/31/07 Armand replace hoses from engine to water heater Armand & Carol Minnie
05/21/07 Duane Simmons electronic cruise control – installed by AJM 265.00 Armand & Carol Minnie
06/20/07 Arizona Mobile Mechanic replace rear main seal on original engine 932.00 90579 Armand & Carol Minnie
07/10/07 Arizona Mobile Mechanic repair L/H exhaust manifold 180.00 92095 Armand & Carol Minnie
07/16/07 All RV new roof air and misc b.s. 1,133.76 92133 Armand & Carol Minnie
07/18/07 Arizona Mobile Mechanic repair & recharge A/C 275.00 Armand & Carol Minnie
08/21/07 Taylor Chevrolet – Rexburg, ID Replace engine – Motor Works, Spokane, WA 5,938.00 94515 Armand & Carol Minnie
08/21/07 Taylor Chevrolet – Rexburg, ID Check transmission 187.04 94515 Armand & Carol Minnie
09/17/07 Lube-it Express Moab, UT change oil 34.43 95020 Armand & Carol Minnie
09/24/07 Arizona Mobile Mechanic replace choke heater tube 74.85 96415 Armand & Carol Minnie
09/24/07 Arizona Mobile Mechanic replace all rubber fuel lines and filler hose 403.25 96415 Armand & Carol Minnie
09/24/07 Arizona Mobile Mechanic replace air filter 12.25 96415 Armand & Carol Minnie
09/24/07 Arizona Mobile Mechanic check brakes – over 50% worn 25.00 96415 Armand & Carol Minnie
09/24/07 Arizona Mobile Mechanic replace turn signal switch & 4-way 118.89 96415 Armand & Carol Minnie
12/03/07 Costco tires 1,305.84 96450 Armand & Carol Minnie
12/04/07 Arizona Mobile Mechanic fix r/h exhaust manifold noise 156.00 96459 Armand & Carol Minnie
12/10/07 Applied GMC Eagle wheels (7) 1,225.00 96450 Armand & Carol Minnie
12/10/07 Applied GMC T-skirts & brackets 95.00 Armand & Carol Minnie
01/11/08 Arizona Mobile Mechanic fuel tank not switching properly 114.56 98861 Armand & Carol Minnie
01/11/08 Arizona Mobile Mechanic fix r/h exhaust manifold noise 138.33 98861 Armand & Carol Minnie
01/11/08 Arizona Mobile Mechanic fix exhaust leak in choke heater 90.50 98861 Armand & Carol Minnie
11/27/08 Coop motor works Onan board 223.00 Armand & Carol Minnie
12/03/08 Arizona Mobile Mechanic change brake fluid – repack rear wheel bearings 417.95 101557 Armand & Carol Minnie
04/14/09 replace macerator pump (again) macerator pump 125.99 Armand & Carol Minnie
05/07/09 Applied GMC electric fuel pump kit 186.00 Armand & Carol Minnie
05/07/09 Applied GMC digital monitor panel 96.70 Armand & Carol Minnie
05/07/09 Applied GMC APC cable 25.00 Armand & Carol Minnie
05/07/09 Applied GMC city water fitting 35.79 Armand & Carol Minnie
06/02/09 Applied GMC transmission vent – hose 18.50 Armand & Carol Minnie
06/02/09 Applied GMC Lumina Wipers and blades 84.95 Armand & Carol Minnie
06/02/09 Applied GMC Buttons and screws for window 3.00 Armand & Carol Minnie
06/03/09 Arizona Mobile Mechanic install electric fuel pump 465.96 104097 Armand & Carol Minnie
06/03/09 Arizona Mobile Mechanic fix transmission leak – still leaking from front 211.80 104097 Armand & Carol Minnie
07/14/09 AJM install house battery shutoff 30.00 Armand & Carol Minnie
07/14/09 AJM install Intellipower PD9245CV power converter 172.32 Armand & Carol Minnie
07/14/09 AJM install city water fitting – take insides out of original check valve 10.00 Armand & Carol Minnie
07/14/09 AJM change oil – Mobil 1 – NAPA filter 104097 Armand & Carol Minnie
09/16/09 AJM Digital monitor panel – installed Armand & Carol Minnie
11/06/09 Applied GMC replace oil cooler lines with JR Slaten’s SS setup 230.00 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace left outer CV joint & boot 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace right knuckle 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace steering damper 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace end link bushings 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace sway bar bushings 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace both lower ball joints 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace bearing on left intermediate axle 107400 Armand & Carol Minnie
11/06/09 Applied GMC repack rear bearings 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace brake shoes on both intermediate wheels 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace brake cylinder on right intermediate wheel 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace plugs, rotor, distributor cap, ignition wires 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace alternator 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace both front bearings add zerk fittings 107400 Armand & Carol Minnie
11/06/09 Applied GMC replace transmission with Manny rebuild 2,298.00 107400 Armand & Carol Minnie
11/06/09 Applied GMC Change oil and filter (wix filter) 70.00 107400 Armand & Carol Minnie
11/11/09 Applied GMC install dual bag rear suspension system 1,231.00 108000 Armand & Carol Minnie
11/11/09 Applied GMC replace mufflers 108000 Armand & Carol Minnie
11/11/09 Applied GMC replace steering boot 108000 Armand & Carol Minnie
11/11/09 Applied GMC replace fuel pump – pressure too high 0.00 108000 Armand & Carol Minnie
11/11/09 Applied GMC replace carburetor with Patterson rebuild 514.00 108000 Armand & Carol Minnie
11/11/09 Applied GMC replace transmission with Manny rebuild – first one failed 0.00 108000 Armand & Carol Minnie
12/01/09 Replace driver’s side windshild with new gasket 108000 Armand & Carol Minnie
12/30/09 Arizona Mobile Mechanic final drive – new seals and gaskets 434.00 109352 Armand & Carol Minnie
04/05/10 AJM install VIAIR compressor and all metal fittings 85.00 111868 Armand & Carol Minnie
04/06/10 Dave Lenzi ride height adjusters 61.00 111868 Armand & Carol Minnie
04/06/10 AJM rotate tires – spare to RF – clockwize – LF to spare 111868 Armand & Carol Minnie
04/06/10 Springfield Ignition Replace distributor & add timing tab (missing from rebuilt engine) 111868 Armand & Carol Minnie
04/28/10 AJM install Shurflo Whisper King water pump 92.22 111868 Armand & Carol Minnie
07/15/10 Arizona Mobile Mechanic install aluminum radiator 1,200.00 114582
07/31/10 AJM remodel interior living space 5,000.00
01/01/11 AJM upgrade rear suspension to quad-bag 500.00
08/01/11 AJM upgrade rear brakes to discs with reaction arm 5,000.00
02/07/12 AJM fuel/vapor separator & charcoal cannister 200.00
02/08/12 AJM stainless hot water heater 300.00
02/10/12 AJM aqueous foam fire extinguisher in engine compartment 400.00 17,615.22
02/21/12 AJM new switches for lights and water pump including in bath 100.00
03/03/12 AJM r & r intake manifold to install blocking plates on exhaust crossover
03/03/12 AJM belt tensioner on A/C compressor 25.00
03/03/12 AJM install Remflex gasket on passenger side exhaust manifold
03/30/12 AJM two new Magnaflow SS mufflers and 2 1/2″ pipe from mufflers back including new “Y” 495.00
04/02/12 AJM ventilation – with remote control blast gates
belt tensioner on alternator 70.00
04/15/12 AJM aux. vacuum pump for brakes
04/15/12 AJM new belts on alternator and a/c 20.00
04/15/12 AJM new fresh-air ventilation 100.00
06/10/12 rebuilt transmission purchased from Steve Ault 600.00
06/11/12 NextGenAuto install transmission 588.00
07/03/12 NextGenAuto install new seals in final drive and fix engine oil leaks 300.00
07/03/12 NextGenAuto replace A/C compressor, hose, and recharge w/R134 1,049.00
07/05/12 AJM fabricate and install center console in cockpit
AJM install transmission temperature gauge
07/12/12 AJM replace Onan mount cushions to fix sag
09/06/12 AJM replace tires (6) 866.00 142000
11/27/12 AJM replace driver’s side outer CV boot, shockmount grommet, install transmission cooler, replace spark plugs, dist cap, rotor, and wires, repair bogie greasers (tire failure) 501.79 145628
08/08/13 AJM reconditioning and retinting all living area windows 1,000.00
09/15/13 AJM new house batteries – 2 6V golf cart batteries 200.00
12/292013 AJM installed surge tank for house water system 100.00
02/15/14 AJM installed new suburban 19K BTU furnace 500.00
03/15/14 AJM body work and paint – repair and paint SMC sides below waist to start 2,000.00

Installing a surge tank for house water system

Installing a surge tank for house water system

A long time ago (during the permanent bed conversion) I installed a Shurflo Whisper King water pump and have mostly been very happy with how quiet it is. The problem is that no matter how quiet it is, it is still audible when it runs. It makes us want to keep the water pump switch in the “off” position (very annoying) because it “burps” every 10 or 15 minutes. It doesn’t seem like much but some of us are sensitive to any noise when it is otherwise nice and quiet and it bothers us.

I figured it was happening because of a small leak in the built-in check valve in the pump. It turns out that a surge tank is listed as one of the solutions to this problem by Shurflo. They also recommend using a surge tank to prolong the life of the pump – so it doesn’t constantly start and stop. I found a nice sized (about 8.5″ diameter and about a foot long) at Home Depot’s web site (a Flotec FP 7105-8).

The photos below show a mock-up of how I planned to measure the pressure in the house water system (22 pounds with the Whisper King even though it claims 30 pounds in the documentation – I guess that could be because of a power issue, so I plan to check) and then to substitute the surge tank for the gauge. I held the tank in place against the back wall by adding a brace in front of it and connecting it to either side of the bed supports. The tank is held well out of the way of the rolling drawer that slides under there too – the horizontal line in the insulation  below the installed tank in the last photo is where the rolling drawer rests.

We plan to use the coach in the next month. I will report on if and how this helps solve our “noise problems.

Update 1/20/2014: We used the coach for a weekend trip – 3 nights – and the surge tank has fixed the problem of the water pump “burping”. We can now leave the water pump turned on when we are in the coach and there is no water pump noise except when the pump runs to refill the surge tank when we use more than around a gallon of water. When the pump runs it does so for about 30 seconds and then stops. Since it is a Whisper-King it is very quiet when it does run so, almost like home. Worth doing.