Good stuff Jon, it's interesting that my 99 chassis is the same as Pauls, but mine doesn't drop when the air tanks are drained. Just goes to show you that the converters do modify the Prevost systems as you pointed out.
Senior Member
Good stuff Jon, it's interesting that my 99 chassis is the same as Pauls, but mine doesn't drop when the air tanks are drained. Just goes to show you that the converters do modify the Prevost systems as you pointed out.
Senior Member
Tom,
Don't be so sure. I would want to review the drawings applicable for both your serial numbers, and then look at both coaches before generalizing. I am of the opinion (which may be all wrong) that the Liberty changes were valving only and the air tanks and their relationship to the air bags was unaffected. I don't know if yours is pure Prevost or if it has the HWH on top of the Prevost system, but I wouldn't be willing to make a bet on this without some research.
Not all tanks are tied to the air bag side of the system (between the ride height valve and the air bags), so I presume some of the tanks are there solely to provide additional volume to the air bag side of the leveling system, and had those air tank valves remained untouched Pauls coach would not have lost air bag air.
For you guys that are always wanting to improve your coach....remember just because it's that way now, doesn't mean it has to stay that way!
Senior Member
Wet tank, both brake tanks and the aux tank drained while on the lift at Prevost and the bags never moved. The two small tanks outboard by the rear wheels were not drained as they would would have deflated the bags according to the Tech Dude. I was there, watched the tanks being opened. I have the HWH along with the Prevost Level Low.
Further, the entire driver rear side was being held up by just the tag axle and bag, as the duals were removed for a wheel seal and the air tanks were empteeeeeee.
Tom, on ours the air stays in the bag until you turn the key on and the leveling valve is in a position to dump air or you dump air yourself with the level low. I can dump all the tanks with out the air bags loosing air.
I installed my new Leveling valves today. These replaced the level low manual valves that I had. I put in a 4 way leveling so I can move the left or right side without the front being raised to keep from twisting the body,
Senior Member
I just want to make sure my previous explaination about why Paul's air bags lost air is understood.
On coach systems prior to Paul's and Tom's there were no air bag air tanks. On earlier vintage coaches their air system has the wet, primary, secondary and aux tanks, but none tied directly to the air bags themselves.
On Tom's and Paul's and XLII coaches it appears that each air bag has a dedicated air tank that is plumbed to the air bag apparently to increase the volume of air available at the air bag. As long as these tanks are not bled when draining moisture from the air system the coach will not drop or change position.
All other tanks in the bus air system can be purged and the bus will remain. I did not trace all pneumatic paths, but it also appears that the rest of the valving arrangement is the same as our vintage coaches with the exception of whatever changes have been made by converters.
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