AJ....(free advice is worth every cent you pay for it) among the POG members I would suspect that one of the most expensive and least rewarding repairs to our coaches has been the air system, excluding the brakes.

The suspension control system consists of valves and airbags and hundreds of fittings. The house is likely to have more devices that require air, ranging from the driver seat to the floor slide and a bunch of other things that vary from converter to converter. If you have OTR the extent of the aux air system runs from the very nose of the bus all the way to the air bellows for belt tensioning.

It is probable that even the most skilled and knowledgable repair facility will eat money out of your wallet faster than a horse eats oats.

I spent two weeks in my garage with my current coach chasing every air leak and getting the system tight enough so the system pump runs only once a day, if that. But I started with a bus that didn't lean and didn't have very many issues. The sources of leaks are endless and insidious. You can do a whole lot yourself and should, unless money is no object. A stethoscope from Sears, a spray bottle with water and kids bubble mix, and a quiet place will be all you need to locate almost all of the ones accessible without going under the bus. That includes the steer compartment and the engine bay.

When you get that done you may have solved most of your leaking problems. But if they continue remember, when the bus is parked there is zero pressure on the brake system so that does not need to be checked other than the pre-trip inspection. That leaves the suspension system. On that, the air bags can have golf ball sized holes in them and if you are shut down, they will not drain the auxiliary system because 3 of the Norgren valves are shutting off flow to or from the air bags.

Now you are down to the pneumatic operators alone under the coach. The rest of the suspension control system leaks would have been in the steer compartment. Since your system is likely to leave pressure on the operators on the ends of the Norgren valve actuators, that is the place to check under the coach. If they are leaking it should show up around the pneumatic operator end cap. That's my bet.

The reason for this treatise is if you understand what I said above....you know exactly where to look and likely now know more than a non-Prevost repair facility.