New Rear Springs W/Airlifts to ALC

It has been over a year since I received my Airlift 1000 kit and it was beyond time to get the wagons back-end back up to at least factory height. The rear has been sagging since I got the wagon. It had the ALC but it was not working and I did not have the time to mess with it. I had new air shocks installed with a manual fill valve in the meantime. Even with plenty of air in the shocks, I would scrape in some driveways and it was driving me crazy. When I had back seat passengers, it felt as if the nose was up for take off! The wagon also leaned to the right in the rear by an inch or so. I always wrote this off to the weight of the full-sized spare on an alloy rim in the right carrier compartment.

My goal has always been to replace the rear springs and use Airlifts in the coils hooked to the factory compressor. Any further adjustments needed beyond that would be with the manual fill air shocks, but I highly doubt I would ever need to.

After reviewing all past posts about rear suspension here and the other forum, I ordered a set if Moog 5419 HD springs. These apparently are the commercial use springs used on the 80's and 90's Chevy and Buick sedans. Thanks to "Convert2Diesel" on our forum for his additional insights with my spring selection!

The process:
I took the front drivers wheel off to access the Automatic Level Compressor to ensure it was operable. Found that it was all hooked up correctly and I had a fuse in the ALC slot yet nothing operated. My assumption is that it had burnt up years ago from overuse or constant running due to air leaks. I had a spare compressor set-up I pulled of a 95 Roady sedan prior. Hooked it up and , Bingo, it worked!

Before buttoning it all up, I modified the compressor to allow for the lower pressure (again using prior fourm posts). This involves removing the rubber bladder/disc from the accumulator tank. What I did was to cut the center circle out rather than remove the entire disc. I reinstalled the compressor and tested again and it was working as it should. I took apart the dead compressors accumulator tank and found the spring and metal disc were completely rusted away!







Next was the new coil springs and the Airlifts. I raised the back end and removed the wheels. Using a set of very cheaply made spring compressors (Harbor Freight), I removed the drivers side spring. It was a pain getting the coil out. I highly recommend an internal type spring compressor as the outside type take up needed space to easily get them in and out of their spaces. Comparing the old and new spring, the new 5419 is 2" taller then what I took out. Not sure if springs traditionally loose that much spring height with age of if these were somebody's past lowering springs.



I compressed the new spring and got it installed. I flattened and zip-tied the Airlift bladder (explained in posts on our forum) and slipped it into the coil. I fed the air line through the top rather than the bottom. This keeps the air lines tucked up higher and safely away from the worst of elements.

Did the same with the passenger side with the exception of having to wait a day for special order coil insulators to come into the Buick dealership. The insulators cushion the top and bottom of the coil spring and the passenger side set was chewed up and disintegrated so I had to replace them. No auto parts store stock them and the dealership had the shortest turn around time to get them in (from Michigan).



I could not locate a small enough fitting that is needed to go from the factory air line running to the back of the wagon that needs to adapt to the 1/4" line that comes with the Airmasters. What I ended up doing was getting a universal tee (Napa and Pet Boys have) that starts at 1/8" and goes up two sizes. So all three stems had this same 3-size set up.



I clipped off the factory end of the air line on the wagon and using a heat gun, heated up the end of an awl and slowly enlarged the end size of the factory line. Heat the awl, push into air line, over and over till you have it large and long enough to go over the 1/8" barbs on the tee. Since I also could not find a clamp this small to secure over the fitting I just modified, I took a thick plastic washer and drilled a 5/32" hole through it. I slipped this over the airline, then pushed the air line over the barbs on the tee, then forced the plastic washer down to force the line into the barbs. And for some added security, I tightly wrapped some fusion tape around this fitting to seal it up nicely. The other 2 stems of the tee are for the 1/4" line from the left and right Airmaster bladders (with provided clamps from the kit).

To ensure that there is always some minimal pressure in the airbags, I put the level adjust sensor arm at position 2 (the 2nd indent from the highest position). This will help ensure the bags get air with less weight added to the wagon. I put 35lbs of air in the air shocks and about 15 in the bags and lowered the wagon.

So the outcome:
Factory Service Manual has the rear trim or ride height to be at 21.9" +/- 1". Mine now sits around 22.5". Most notable differences are that it looks, feels and drives 100% better! The right side lean is now gone, I still have that smooth Buick luxury ride and the wagon no longer leans when conering (more due to the airbags I believe). I have been driving around doing extra errands to burn through the tank of gas to fine tune the level height adjuster to ensure the compressor comes on as weight is added. As the tank is getting emptier, the trim height has remained the same!

I LOVE THE RIDE NOW! I always liked the Roadmaster "floaty" feel, but after you drive it when the suspension has been tightened up a bit, it is even more pleasurable! I know many put on sway bars and that is still something I may do in the future but I have no plans of towing so not sure I will really need one.

Now, with HD springs with Airmasters and air shocks and with a full tank of gas and 6 passengers and still bottom out, I will go absolutely bats!

Way to go. I plan to do that with my car, too. Do you have any better pics of the modifications you made to the compressor? I never had one apart and am not sure what you gained by cutting the center out of the disc? I know you do something to lower the air pressure, but not sure what...

Oh, and rear springs are simple to do WITHOUT a spring compressor. Just disconnect the lower shock bolt (one side at a time!) and pull the old spring out and stuff in the new one. Reattach, rinse, repeat on other side. WAAAAAY easier than trying to mess with compressors. Next time.

Nice work, man. I loved the way my car rode with the bags in the springs. 10lbs in them and it was like there was a sway bar back there. Cornered flat and rode awesome.

Good work Lance:

Just an aside here, the stock GM compressor is able to pump out over 110 lbs. Try to find a limit switch to keep the maximum below the max bag pressure (50lbs???). Anyone who works with pneumatics will have a 12 V version. Plumb it inline with the main feed line and you should be good to go. A 50 lb blow=off valve would also be a good addition. That was the issue I had with the bags. I would hook up the trailer and pump them up to around 35 lbs. but with the added volume of the bags, when I went over a severe bump, the suspension travel would force the bag pressure over it's design pressure and they blew out, or the added pressure forced the bag out through the spring coils and when the suspension went into rebound, would actually pinch the bag. Same result. Instant lowrider.

Bill

Thanks Toomanytoyz. I didn't take anymore pics of the compressor mod as there are already photos of the mod on the forum. What I did different then those posts was instead of discarding the rubber disc altogether, I removed the center of it and reinstalled it. The center is what maintains the higher pressure that is needed/used for air shocks. By removing just the center this allows the lower PSI pressure that the bags use. The Airlifts cannot have more than 35lbs of air in them and with the rubber disc mod I recall the max pressure will be about 14-15 lbs. More than enough to raise the trim height to level under load.

As to the springs, I read that some folks didn't need spring compressors, others did. I did as you described. I had the shocks disconnected and the suspension was hanging and I even used the floor jack to hike up the opposite side a bit to give the spring room to come out but no go. So, not sure why I had the struggle but glad I had the spring compressors on hand to get the job done.

Very good article,easy to understand and well written. Question for you, do you have the
pn's for the rubber insulators for the rear coil springs? I dont know if they are used top and bottom,but if they are I would like both pn's. Sometimes when we replace parts ,its hard to tell the difference,but other times after replacing something the entire car just seems better, thats what happened to you. Good luck, ed

The rubber coil spring insulators are the same for top and bottom. The GM part #10247105. Moog #K62032. My reccomndations is to replace with fresh ones if you ever change coils. Get them in advance from the Internet for as little as $5 a piece. I visited 2 auto parts stores that didn't carry them and couldn't order them and I called 3 more and found only one that could order them and it would be about 5 days to get them in. The dealership got them in next day for me but I did have to pay $15 for shipping but I was in the middle of the job and needed them right away.

So are they sold in pairs?

They were only offered individually. The part numbers I provided are for 1 each.

Noted.

Thanks for info. Planning on new rear springs soon.

So an update here.  I have been chasing a slow leak for sometime now and could not find it.  It was either at the bags or the compressor head.  Well I decided to pump them up fully and crawl under the wagon. Heard noise above the drivers side bag. Jacked her up and took off the wheel and sure as heck, an audible leak at the airbag fitting at top.

What a pain. Had to take the airbag out and see below for what I found...




So it looks like there was rub where the hose goes through the top of the coil spring housing. I didn't see a way to prevent this and the directions do not describe how to prevent this possibility. I called Airlift today and spoke with a tech. He just kept saying that it was "odd" and "unusual". I offered to send them a photo and they declined. I asked if there was any records kept from other specific model owners that call in that perhaps there was a fix for this. Nope.

So, being creative, I had to come up with something on my own. Hopefully it helps others. I went to Home Depot and found Stainless Steel braided Toilet supply line ( be sure to get the stainless steel and not the poly braided; better abrasion resistance). I tightly wrapped each end with fusion tape prior to cutting the ends off as there is risk that the braiding may come slightly undone. I cut the ends off and then gave the entire length a wrap of the fusion tape for some extra abrasion resistance.



I slid this over the air line and reinstalled the line on the airbag. Then I pushed the braided cover down as tight and close to the bag as possible. If there will be rub again, my hope is that it will take a long long time before it would ever reach the air line. What is alarming about this is that a wagon occasionally needs to be lifted for tire changes, etc, and there would always be risk that the line would not rest back down perfectly centered in the coil spring upper mount hole so I am surprised there have not been others with this identical problem.

So I put everything back together and added air and son of gun if the passenger side wasn't also leaking in the exact same spot!!!

I had to do the exact same procedure to the other side.

Long story I know but as of now, she holds air fine and all is working well (knock wood).

I just hope this is the end of messing with these bags. So much for being carefree!

Crap I'm getting ready to install these same bags in Ms. Roadie. What exactly was the hose rubbing on? The big red insulator pad? the spring itself? Do you think maybe the hose was to long leaving to much slack which resulted in the rub/wear? I don't want to have to pull the bags off in a year to find a hole in the air hose.

No the hose was not too long. You need to leave a little slack for movement. At the top of the coil spring bracket/holder there is a large hole about an inch in diamater. This is where the air hose runs through. You can see from the photo that at some point there must have been too little air which allowed the airbag to move slightly and when the air refilled, it must have been at a slight angle rubbing the tube against the one inch hole.

Airbags are worth doing as it really is a great way to get the lift you need and I love having it connected to the factory air compressor. I just do not want to be repairing them once a year!

good tips, thnx for sharing
Pete