air leveling system

[bergdoll]

HELP! got the bus ( 1982 prevost champion/marathon -same as le mirage different windows) running after 2 years of sitting & have 100+ psi on the dash guage but... the bus is not airing up (bags), so i put the shop compressor on the inlet valves (front & rear) & got the front bags up & drive axle bags up but the tag axle stays flat... also it didn't air up the bags w/ engine running but dash reads 100+ psi & fairly fast to reach that air pressure...
i hear no leaks at all. any help/info. would be greatly appreciated.
                                  bobbybergdoll@yahoo.com
if any of you can write to me directly i have pics of what i suspect might be the problem & the manual says to "take apart & wash with warm soapy water & dry & reassemble. i just want to make sure i am taking the right things apart., & i've only found 2 of them. 1 in the steering compartment & 2nd in the rear passenger side.

[gumpy]

I've been trying to help this fellow via email because he was having some problems posting. I'm not familiar with the Prevost in particular, and air systems are one of my weak areas in general.

Here are the photos he sent me. One is kind of small.

I believe these are just filter screens / moisture traps and/or regulators, probably on the front suspension or possibly door/step/lock accessories, and maybe some belt tenisioner or radiator shutter control in the rear. 

I suspect this is not where his problem is, but probably is related to a shuttle valve or check valve somewhere that's stuck. I'm sure some of you Prevost guys know more about where they are located than I do.


craig

[gumpy]

Bobby, I just noticed your description was a bit different than the one you sent me the other day. It looks like you've made some progress on your problem, and it appears you have the fronts and drivers aired up now, though maybe only with shop air? Still probably a stuck valve someplace, and your air fittings are bypassing the brake portion of the air system and going directly into the suspension/accessories portion?

As for the tags, make sure you don't have the isolation valves turned off (if the Prevost has them). On the MCI, there are two valves in the rear compartment door that allow you to shut off the air to the tag axle bags. Don't know if the Prevost has them.

craig

[prevost82]

I have the same bus... If the tag is not airing up you should have a air switch that sez "Wheels Up" That is for your tage axle.

Ron

[plyonsMC9]

Any updates on this Criag?   I didn't hear back from Bobby after I offered assistance - maybe the email didn't get through one way or another.

Best Regards, Phil

[gumpy]

Haven't heard from him. I'll send an email.

[bergdoll]

hey all! got it fixed & drove to Indiana from california. replaced some air stuff & when i got out there found out that i need to replace  (tag axle) another bag. stayed up though. air went to the next weakest point. learn by doing...

[gus]

Just for general air bag info which probably does not apply to this situation.

My recent problem with my 4104 RR failure to inflate turned out to be a stuck external check valve on the leveling valve. This is a tiny valve about 7/16 x 3".

This was kind of new to me because the usual problem I've had with check valves is their being stuck open.

I shot it with some penetrant, blew air into both ends a few times and it is now working fine.