Aux Air System Leaks

[Lee Bornstein]

My 97 Liberty Classic has developed a leak in the Aux Air System. Small electric compressor used to run about every 12 hours. Now it's going on every 15-20 minutes. Compressor runs till pressure reaches 75PSI then stops. Starts again at 55-60 PSI.

Only Items I know of that run from this compressor are: Bed Lift, Black Dump Valve and Grey Bypass Valve. I've checked the control valves and fittings for those three items and no leaks. Don't have Air Operated Pocket Doors.

What an I missing?

Lee

[MangoMike]

Lee,

In the drivers steering bay is where the air feeds these lines.

Air comes out of this xmas tree at the shut off valve on the left.

434

Then feeds into this manifold, then off to bed, chair etc.


433

Soap spray all these connections.

Hope this helps.

Mike

[rfoster]

Lee: Don't forget the floor slide/step cover, and entry door lock, and drivers seat. Maybe even the generator air bags, air conditioner bellows, engine fan bag. The valve over the engine doors was/still is leaking on mine.

[Lee Bornstein]

Roger:
Believe floor/step cover and Door Lock are on operated by air produced when engine is running. I will trace hoses and see what I can determine.

Lee

[dalej]

And the level low or air bags. If the air is leaking out anywhere to do the leveling air bags it will loose air and the aux. tank need filled.

[Lee Bornstein]

Have isolated problem. Removed and capped air hoses at manifold as shown by MangoMike. The hose going to the Grey Bypass/Black Dump valves is the culprit. Once that line was capped havent had compressor run in over 3 hours so far.

Tomorrow I will go further on that air line.

Air Lines on my manifold are as follows:
1. Fat Hose Air IN from Aux Compressor
2. Fat Hose Air Out to Prevost system (Via Converter Valve)
3. Thin Hose Out to Step floor cover valve
4. Thin Hose Out to Bed Lift valve
5. Thin Hose Out to Waste Dump Valves
6. Fat Hose Out to someplace under the dash - dont know what it is yet

[lewpopp]

Has anyone rebuilt the small compressor in the front left of the coach. I replaced it and kept the old one and looked into the rebuilt kit, but I have as of now not worked up enough guts to order the rebuild kit. I have no idea what it will entail.

Lew

[dalej]

If it's a Thomas it cost about as much to rebuild as replace. I know it's hard but seem companies just want to throw stuff away. Mine they wanted 2oo and something for the kit, I bought a pancake compressor for 160.

[truk4u]

Lee,
Anything that runs off the aux tank will cause your aux compressor to run if pressure drops after engine shutdown. Your airslide would receive it's air via the aux tank and not directly from the engine compressor. Be sure to check the airslide regulator (in the steering bay) with soapy water. Mine leaked and I took it apart and replaced an o-ring.

[lewpopp]

Dale

Did you put the pancake compressor in the steering bay? How did you mount it? How much pressure can you get? I'd like to change my air reel to that if I can get enough to pump tires to 110 lbs. Could I trouble you to show a picture?

Lew

[win42]

Dale: Make, model and source please. I do not have a aux compressor, but would like to get one. 12V

[Lee Bornstein]

Tom:
Where's the Aux Air Tank located?

My Air Line runs as follows:

Aux Compressor > Pressure Switch > Distribution Manifold > Converter Valve > Prevost System.

Manfiold distributes air to Bed Lift, Sliding Floor, Dump Valves and someplace under dash.

Converter valve allows me to segregate Aux Air from Prevost system - don't know why it ties into prevost at all. Anyone knowlegeable on this??

[dalej]

Lew I put the pancake compressor in the Generator bay (1st bay port side) to clean up the steering bay. I like to have the steering bay clean, there is a sign that told me "keep this bay clean" and besides I gave the steer bay to Jan to store her purchaces in while traveling.;)

Notes: Bought it at Sams Club, shuts off at 135 pounds, 120VAC, using a water filter, 50 foot hose, I take it out and carry it to the trailer if it needs air or if someone else needs it.

One of the things I like most about it is after the bus has been sitting around here for quite a while, I just turn on the compressor and when it has the tanks full, I turn on the key switch one turn and the bus airs up without starting the detroit.

[MangoMike]

Lee,

The "someplace under dash" is probably for the air operated louvers to control air to the cruise airs behind the bumper.

MM

[truk4u]

Lee,
We need Jon to jump in here, same make and year, I'm confused on your setup. Are you saying that the aux compressor does not feed the aux tank? Unless Liberty does something different, the job of the aux compressor is to maintain aux tank pressure to run all the air needs we have been discussing, while the engine is shutdown.

My aux tank in located up front, to answer your question.

Jon?

[Jon Wehrenberg]

I assume you are discussing Lee's aux air. Yes his compressor charges the aux tank and system, but will not charge the brake system.

His aux tank may be over the front axle, but he has a different year and a 40 foot coach so it is likely to be different than mine, Roger's or Mangos.

BTW I think Lee did a fantastic job of isolating his problem. I use the soapy water and ears (sometimes helped with the stethoscope), but he cut to the chase and isolated the portion of the system that needed to be fixed.

This group is going to be able to tackle any problem, no matter how complex more quickly and reliably than even Prevost can and I think the speed we are amassing skills and knowledge is awesome.

[Lee Bornstein]

Found It!

The Air Cylinder (push-pull) that operates the Black Water Dump Valve is leaking and needs to be rebuilt. If I set switch to close Dump Valve I don't loose pressure. If Valve is open I loose Pressure within 10-15 minutes.

Had to cap the outlets on the Air Solenoid Valve to verify the source of the leak was the Air Cylinder and not the Solenoid Valve.

Cylinder is Aurora Air #S-1529 - Rebuild kit is 07522-B available from Aurora for about $8.00.

Thanks to all for the feedback.

Lee