View Full Version : Dumps air after 5hrs in rear

12-23-2018, 01:31 PM
Hey guys new prevost owner with lot's of questions. Recently bought my first prevost. 86 xl40 marathon conversion. Don't think it has the norgen system since I have toggle switch and 3valves to set height by entry door. After about 5 hours it will dump all the air out of rear suspension in a matter of seconds. front will remain at ride height. Air pressure will be around 70 psi when this happens. Any ideas on where to start looking for my problem and are there any referrals on someone in the Midwest with prevost knowledge ? Thanks in advance.

Joe Camper
12-23-2018, 07:22 PM
Your chassis is an 84 or a really early 85 if u have the 3 seporate up and down buttons.

At about 70 psi the tag lift looses sufficient pressure and it releases and the tag goes up, that is whats happening
Mine was an 84 too. U can get the aux air leaks to a minimum and leave the aux air compressor running. That's fix 1. I've seen some marathon without aux compressors if u don't have one u may want to get one.

That is a moving target and could prove to be a character builder. Depends on how well your chassis wants to cooperate.

Try this. If u have a good airtight set of drive axle bags and u r already on a flat spot. Before turning the bus off go all the way up with both left and right rear with the buttons, be patient its slow, and then raise the tag and turn the bus off. When u do this the back will settle back to ride height and when the aux air pressure falls off and the tag releases it's already up and nothing changes.

I have a home in Chicago and unlike last year I plan on being there this coming year. U r welcome to call me anytime. I can help u.

12-23-2018, 08:21 PM
Thanks joe. I got your# off of another thread so I will give you a call after Christmas. My bus is titled as an 86 with conversion in 88 so don't know why it would have to older system but from what I'm reading I'm sure it does. Is this# correct ? 708 243 7871