[Dmatz]

As mentioned before placing blocking under the Cisco before you work on your air system could be life and death. DO NOT OVERLOOK THIS STEP. Prevost recommended replacement if the norgen valves I assume thus is the six pack referred to every 10 years as well as the air bags and break chambers. I am not sure what Newell's recommendation is or what everyone has found for lifespan of these items. The advice was to change them in a shop vs being down on the side if the road. Air leaks can be tough to track down I do agree with the advice given here as well.

[77newell]

Lance: If it were me I would be first checking the drains on the bottom of my brake tanks - they are the two front ones on my coach. If your brake tanks are dropping ahead of the supply tank then there is a leak in the brake supply system, but not the brakes themselves since they are under pressure only when braking - except for the emergency brake canister when running down the road, so if pressure is dropping when parked the leak is somewhere between the outlet of the pressure protection valve on the supply tank and the inlet to the brake control valves.

Then I would go after the leveling system. If the coach drops with the HWH in the manual mode, then it is not the height control valve (HCV) since the bags are isolated from that valve in that situation. The bags can only leak down by air from the bags escaping to the atmosphere which is lower in pressure. With the HWH in the manual mode and pressure being maintained in the supply tank, do the bags deflate? If yes then your raise valves in the six-pack are OK. If no, then those valves are leaking. If with the HWH in the manual mode there is air leaking (bubbles or leak detector - I prefer bubbles for this one) then at least one of the down valves is leaking. If you use the HWH to manually raise the coach and the HCV's start exhausting then the six-pack valves isolating the HCV's are leaking. There are also orings that can leak local to the solenoid valves on the six-packs.

On the front of the coach in the space behind the front fascia below the driver seat my 93 coach has a manifold with 6 taps on it, these are for other uses of air from the supply tank to be checked by blanking them off and seeing what your pressure does. On my coach this manifold is where the supply pressure gauge gets its pressure.

[Fulltiming]

Last time I checked with Newell, they were recommending that the HWH leveling solenoids be rebuilt or changed every 3 years. Mine are lasting much longer than that but eventually they will leak.

[Richard]

One of the useful tools that many of us have made to help with air leak diagnostics is a shut off valve with guages on both sides that we insert between the six pack and the air bag line. Inserting that tool tells you a lot about where to start.

In your case, if you air up the bags and shut the valve, and the coach squats, then you have an air bag or tank leak. If it stays up with the valve shut, then suspect the valves in the six pack.

If you shut the valve and the pump will build pressure, then suspect a problem with the travel solenoids or height control valves.

[tomgauger]

Hi gang--
Is there a dryer on the air system that operates the doors, seals and toilet? A Prevost dude (ex-Liberty) told me that water on those systems are the main reason for door actuator failures.
Tom Gauger
Working on buying an '04
2001 Monaco Exec.

[lbrachfe]

Just had a door dryer pop a few months back. I just removed from the line , applied new fitting and tossed cracked dryer in trash at Newells suggestion.