Inside the last bay on the top back wall near the exterior door on the drivers side there will be a plate with 4 screws. The plate measures about 6"x6". Remove this plate and you will expose the left rear valve. By opening the main power cutoff switch door on the passenger side, you will expose the right rear valve. The front valve is located right in the center of the coach just slightly back and above the front axle and can only be accessed by jacking and blocking the coach. Because the front valve is so hard to get to and dangerous plus your concern is in the rear, I would start at the rear to check for leaks. One question before going further, do you start the coach with the level low switch in drive position and then the coach goes down as you drive? If you put the level low in manual position when you start and you have a leak in a hose/vavle, then the air will leak out and the solenoid will be closed that would normally be open to add air from the normal source when the level low is in drive position. If this isn't the case, read on.
1. Remove and open to access panels/doors as mentioned above.
2. Air up the bus in the parked position, then shut off the engine.
3. listen for any leaks, also spray the valves/hoses with a spray bottle containing a liquid soap/water mixture. if a leak is present, you
should see bubbles. You can also go to a propane store to buy a leak detecting mixture they sell.
4. If normal, while the bus is still up, crawl on your side between the rear duals and the tag in just enough
to visualize the
two air bags on each side, all four should be fully inflated. BTW, you can crawl in there while the bus is down so safety isn't a
concern but of course, you won't hear any leaks if air supply is zero.
5. Before jacking and blocking the coach to look at the front valve, check the connections on the level low switch by removing the
panel near the drive that contains the switch, it may have come loose (although not likely with your description).
6. If switch okay, then jack the front according to the manual and block it according to the manual
to check the front valve,
although as mentioned, I don't think that is your problem. BTW, some coaches have a small access panel at the back of the spare
tire compantment that allows you to access the front valve without jacking/blocking. Mine didn't
7. If all this fails, there are a number of solenoids in the level low that control air movement and a whole slew of hoses, so contacting
prevost is probably your next best bet. As an alternative, call around in your area to commerical bus businesses until you find one
that runs prevost. If you find one, and I am sure there are several in MI, ask if they will look at your coach. As another alternative,
the shop manager at the Jacksonville Florida Prevost has been very helpful to me over the phone with problems. Other locations
have been hit and miss for me. As one final alternative, there is a prevost owners site that has a bulletin board you could post to
, lots of years of prevost experience there as well as coaches for sale that you can drool over!
I have a 91 LeMirageXL with only 89,000 original miles. The right side used to go down in 2-3 hours. I found a leaking right rear valve, and an airbag hose that had a leak. Fixed both them by getting a new valve from Prevost, $38.00 and had a hose custom made at a local truck shop for $35.00. Front valve is still leaking so the front now goes down quickly but I haven't taken the time to jack and block the coach, lots of work and a safety necessity. Don't have pit in my barn, unfortunately, just gravel floor.
Hope this helps in some way.