So what did you do to your GMC today?
- Thread starter RvRev2
- Start date
Over the last two days, the wife and I went over the rear drums. Installed all new everything. She did the shoe replacements on all four. (In all my years of working on cars, Ive never done drum brakes. I guess I can say I still havent LOL)
I made up the new short bogey brake lines, reassembled all the lines including the braided T. Bled the system, fixed a few leaky fittings and verified that all the drums stopped spinning when the petal was pushed.
Installed the four new Ions on the rear and we have a completely different looking ride now. (Also, anyone with Ions, what was the torque spec for the lugs if you dont mind sharing)
We got the rear back on the ground and jacked up the front. No loose bearing movement, but drivers outer CV is ripped. Replaced the shocks and called it a weekend.
I made up the new short bogey brake lines, reassembled all the lines including the braided T. Bled the system, fixed a few leaky fittings and verified that all the drums stopped spinning when the petal was pushed.
Installed the four new Ions on the rear and we have a completely different looking ride now. (Also, anyone with Ions, what was the torque spec for the lugs if you dont mind sharing)
We got the rear back on the ground and jacked up the front. No loose bearing movement, but drivers outer CV is ripped. Replaced the shocks and called it a weekend.
took mine on its first test trip, just to columbus and back, 260 miles, mostly 60-65, but a 20 minute stretch from 75-80, and a 5 mile hilly detour thru amish country to see how hills felt...and got 10.3 mpg!
thinking at 60-65 on flat highway 12 might be possible? tonight drained/flushed the water systemand lo and behold everything works...filled the propane, fridge works on gas- dunno if its working on 120 also or not, will have to check for that.
only thing not working is the air compressor, prior owner said he pulled the fuse got tired of hearing it cycling, just filled bags manually- compressors new, gotta find where he pulled fuse from... furnace/thermostat works, on demand water heater...
went and picked up blankets/pillows, snacks, water, some frozen stuff, its ready to go camp in... 'roughing it' LOL... I felt bad not tent camping but in a low buck box trailer, with diesel heater, big battery/inverter/etc... but this things like a hotel room
anyways, first trial passed with flying colors, really happy with MPG.
my 'overdue for the groomer' co-pilot loves the big windows, she often sits in back, watching folks behind us
Tim
thinking at 60-65 on flat highway 12 might be possible? tonight drained/flushed the water systemand lo and behold everything works...filled the propane, fridge works on gas- dunno if its working on 120 also or not, will have to check for that.
only thing not working is the air compressor, prior owner said he pulled the fuse got tired of hearing it cycling, just filled bags manually- compressors new, gotta find where he pulled fuse from... furnace/thermostat works, on demand water heater...
went and picked up blankets/pillows, snacks, water, some frozen stuff, its ready to go camp in... 'roughing it' LOL... I felt bad not tent camping but in a low buck box trailer, with diesel heater, big battery/inverter/etc... but this things like a hotel room
anyways, first trial passed with flying colors, really happy with MPG.
my 'overdue for the groomer' co-pilot loves the big windows, she often sits in back, watching folks behind us
Tim
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Whoa that's some great mpg!
Please continue to keep track of it. I suspect you will find that there's too much variability in filling the fuel tanks to get an accurate measurement from one fill up.
Here are my last several fill-ups, and I was purposefully trying to fill the tank the same every time:
I got 11.79 and 10.82 for two of my fill-ups. If I just measured one of those, I might think that was my mileage!
But the rest of the picture shows the real scenario.
Zooming out even further, here's the data for the last 25,000+ miles : https://www.fuelly.com/car/gmc/tze/1976/tmsnyder/963498
Average is 8.3 mpg
Fuelly.com makes it easy to log these as you travel, highly recommend that page, and cost is $0
Awesome test run! "camping" in these is a blast! Way better than tenting. Wait until you take a trip in one, the traveling is the best part, having a kitchen, bathroom, and bed with you the entire time is amazing. I highly recommend staying at a Cracker Barrel for the night. Spend the money on their breakfast the next morning instead of a campground, it's tough to beat!
thanks for the tip- will start logging fuel that way too
I always heard they got 8-10 range, was hoping it wouldnt be like 5 or 6 as then would be into tweaking things...when it got 10 (even once) figured must be running pretty decent.
kinda hoping level/highway like I-70 or I-80 at say 65, might eek 12 out of it? only time will tell
planning a couple colorado trips from ohio... climbing to 8000 feet bet it will struggle to eek out 3-4 on the fillup variability, i can see that, it gurgles for a minute after filling as the tanks balance out- i did use same pump/same station, filled slowly on first notch- with all that gurgling and length of fill pipe, imagine theres a gallon or three of airspace...
just joined the fuelly thing- thanks!
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9/16-inch lug nuts typically require a torque specification of 120 to 150 ft-lbs. This range applies to many 8-lug trailers and light trucks, though specific vehicle requirements vary. Always tighten in a star/cross pattern and verify with your owner's manual or wheel manufacturer.
9/16" Lug Nut Torque Specifications
- General/Typical: 120 - 140 ft-lbs
- Trailer (7,000 lb axle): 120 - 135 ft-lbs
- Light Truck/Heavy Duty: 125 - 165 ft-lbs
- Aluminum Wheels (16-17.5"): 120 - 150 ft-lbs
- Sequence: Use a star or crisscross pattern to ensure even pressure.
- Two-Step Method: Snug all nuts to 40 ft-lbs first, then torque to the final spec in the proper sequence.
- Re-torque: Check torque again after the first 50–100 miles.
When I bought my ION's I was told to torque the nuts to 135, wait a week or 50 miles or so and do it again. It's worked for me.
That's exactly what I thought too, you have it running well!
That final fillup on my graph was 5mpg and is an indicator that something is wrong. I was seeing very lean AFR readings on my wide band O2 meter during that tank, 18-20, so something is going on with the carb b/c last year it was running perfect under all scenarios. This tank of fuel was the tank I filled with and put away for winter storage. It's was sitting in the tanks all winter.
As soon as I put fresh fuel in it, the AFR numbers returned to normal. Very odd.
I made it home to Kansas from the Spring Rally. I fought vapor lock on the way home. Made the driving miserable. Some have suggested replacing the two port mechanical fuel pump with a three port fuel pump. The third port would be a recirculating line.
Question 1: What is the part number for the 3 port mechanical fuel pump?
Question 2: Where do I run the recirc line to, all the way back to the fuel tanks, or to the fuel filler line?
Question 3: How do I connect into the tank or filler line?
Question 4: Rubber fuel line, or hard tubing?
AND, if anyone has done this before, could you send me what you did and pictures would be very helpful.
Thanks all.
Question 1: What is the part number for the 3 port mechanical fuel pump?
Question 2: Where do I run the recirc line to, all the way back to the fuel tanks, or to the fuel filler line?
Question 3: How do I connect into the tank or filler line?
Question 4: Rubber fuel line, or hard tubing?
AND, if anyone has done this before, could you send me what you did and pictures would be very helpful.
Thanks all.
Well, last Friday...
Picked-up the coach from a local brake and alignment company that is familiar with these beasties. It was in because the ride had gotten "rough" after replacing three tires since the last time it was in (the storage facility I use seems to kill tires). They balanced 7 tires and shaved 6 ("trued"). OEM steelies (radial version) and Firestone Transforce.
It now rides like butter on the highway at 65+ (ok, got it over 70 for a few moments). I mean, it rode much smoother than when I bought it after the first time I had this done (late 2024?), but it's even more smooth now. The cost is high (almost $900), so I doubt I will do it again. Time to start buying a couple of Ions and 16" tires every year or so.
TLDR version; I LOVE driving this coach.
A couple of years back I didn't think I could get here....
Side note; switching to EFI seems to have cured my "pinging" using 87 octane fuel. I've had to use premium for a few years to avoid that situation. Now, I no longer ping with 87 after moving to EFI.
Picked-up the coach from a local brake and alignment company that is familiar with these beasties. It was in because the ride had gotten "rough" after replacing three tires since the last time it was in (the storage facility I use seems to kill tires). They balanced 7 tires and shaved 6 ("trued"). OEM steelies (radial version) and Firestone Transforce.
It now rides like butter on the highway at 65+ (ok, got it over 70 for a few moments). I mean, it rode much smoother than when I bought it after the first time I had this done (late 2024?), but it's even more smooth now. The cost is high (almost $900), so I doubt I will do it again. Time to start buying a couple of Ions and 16" tires every year or so.
TLDR version; I LOVE driving this coach.
A couple of years back I didn't think I could get here....Side note; switching to EFI seems to have cured my "pinging" using 87 octane fuel. I've had to use premium for a few years to avoid that situation. Now, I no longer ping with 87 after moving to EFI.
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Just my opinion. The 3 port fuel line is a bad answer. Adding fuel line that can fail and cause a fire in the engine compartment is not very smart in my opinion.
I also do not feel it really solves vapor lock.
What is proven to fix vapor lock is an electric fuel pump as close to the gas tank as possible.
I had a simple “aux” fuel pump on my gmc for 9-10 years and it always fixed the vapor lock issue. When it was hot as hell and the engine chugged, a quick switch to aux on the dash took the vapor lock away. I am on efi now and no vapor lock running 100% electric fuel pump.
My friend’s gmc has been working that was as well for 10+ years.
I know so many others running the same way.
I had a grand wagoneer as well. Pushing fuel fixes vapor lock issue.
But supposedly people have said the 3 port fuel line”helped”. I just go to our July rally in the peak of summer, and there is not one coach of 20 there that is running a 3 port mechanical fuel pump.
I looked in to having my new tires shaved (true'd) , but only got bewildering looks from everyone I asked.
How to cure vapor lock.
1 remove mechanical fuel pump, block off the port
2. install 2 Carter 4070(?) electric pumps under the coach right in front of the tanks.
3. Use the selector switch to select a relay which selects which pump runs.
4. don't forget check valves to prevent back flow through the not running pump
This would be a great topic for its own thread. This thread is titled 'what did you do to your coach today' Perhaps the moderators can move it over to the appropriate sub forum.
Apparently it's not common. I was told this place is the only location for that service in this area.
We had two external Carter 4070 fuel pumps with the carb then switched to in tank pumps and efi.
https://www.gmcmi.com/wp-content/uploads/2013/02/In_tank_Fuel_Pump_Presentation.pdf
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