I just replaced the rear air bag (springs) on my coach. We did the fronts last November and the rear a few weeks ago. We also replaced the front air bags on the Gilling chassis with solid axle. We had a pit available to us. I am not sure we could have done it without the pit. The front was independent suspension. Most of the work was done from the top after we remove the wheels, but we need to pull more air line to reconnect the air bags, that required releasing some clamps from underneath. We spent a day on each side and that included the parts run. Second side was faster. Air lines were what took a lot of time until we figure out it out.
On the rear we removed the wheels to get to the air bag mounting bolts. We worked from both the pit and wheel well to get the air bags out and in. There were 2 on each side. Again it took a day for each side.
What we learned:
Getting the air line off the fitting was impossible. There is a stainless nipple on the inside of the fitting that is sort of pressed in to the fitting, the ferrule crimps the air line to the nipple and we could not get it off the fitting. We cut the air line at the fitting nut, and then removed the fitting. The fitting had to come off to get the mounting nut off. Once the fitting was off we were able to cut the ferrule off the air line and remove it, then it was cleaned up so it could be reused on the new air bag.
We spent a lot of time installing the air lines on the front. The trick we found that worked the best was assembling the fitting with a short piece of air line and tighting the nut until the ferrule can't move, then slide short piece of air line out and the air line in then tighten the nut to crimp the ferrule. We bought new ferrules, nuts, splices and air line at the truck store. With all that being said I would consider using DOT approved Push/Pull fitting. (Google "dot push to connect air fittings ") Theses fitting have O-ring to seal the air line. You simply push the clean air line in and it locks in place. On Gillings chassis the air fitting on the air bag were difficult to get to so we found an easier location and spliced the air line using the Push/Pull fittings. On my coach the air lines were 1/2 inch in the front and 3/8 inch in the rear. The Gilling's front were 1/4 inch. We went to get parts after we had one of the new air bag installed.
On the rear we did one side at a time by jacking one side at a time. It would have worked better to jack both sides. That would have allowed the axle to drop farther and the air bags would have come out and gone back in easier.
We were able to collapse the air bag, (remove the plastic cap) then put the plastic cap back on and it would stay collapse for a few minutes. This helped during installation.
The replacement of the air bags on the Gilling chassis was more interesting. The air bags are mounted to plates. The upper mounting plates were not a problem but lower mounting plates were a little convoluted. Two of the air bag mounting bolts are covered by the axle. It looked like you could unbolt the mounting plate from the axle perch and the air bag would come out. But that didn't work. The mounting plate has slots in it to prevent the axle mounting bolts from turning while they are tightened. But during the factory assembly, they tack welded one axle mounting bolt to the plate. We had to drop the axle to get to all the air bag mounting bolts.
My coach has front and rear Ridewell suspensions. We found the manufactures label plates and emailed Ridewell that information. They provide the part numbers for the airbags.
2000 Country Coach Magna
CAT 385HP Allison 6sp
1998 Saturn SW2
