overnight air loss

[davidbrady]

Al,

All of your house air driven items get their air from the accessory tank. The tank is located located above the front axle next to the secondary tank (used for the steer axle brakes). There's an air dryer and a manifold block located in the outside compartment under the driver's area. The manifold block controls your level-lo and supplies air to your suspension air bags. The accessory tank is protected by a pressure protection valve (PPV). There's another PPV installed on the manifold block. Each PPV is set for 75psi. If your primary and secondary tanks dip below 75psi, then the PPV's block off air from your accessory tank and manifold block, or it at least they should. If your secondary and primary are dipping below 75 psi then you have leaks either in the brake system itself or you have leaks in the PPV's or the manifold block, or it's associated tubing, connections, and valves. I know, doesn't help much... Your best defense is spray bottle of soapy water. Don't go under the bus! (People are killed doing this)! Just focus on the manifold block and fittings in the driver's side compartment. Searching for leaks any further is too dangerous and should be left to Prevost. They'll get in there with soapy water and they'll pretty much solve the problem.