[Glenn and Laureen]

Attached is a photo of the small, canister-like Skinner valves in the rear air 6 pack I referred to in this thread several days ago. I call them Skinner valves because the Skinner company made them per the name on the front (now owned by Honeywell, apparently). I don't know what other people call them or what they are for. They seem to be directly related to an air leak in my supply system. There is one of the these valves attached to each of two MAC valves in both my six packs. I am guessing those two MAC valves are my travel valves [EDIT: Wrong. The MAC valves the Skinners are attached to are the down valves.] The third Skinner valve in this photo is attached to the air pressure regulator/dryer unit with the polycarbonate bowl that collects water and oil.

Anyway, with the engine off but the ignition switch in the on position, each of those Skinner valves is magnetized and the two associated MAC valves are venting air out of the #1 port (lower right side as you look at the front of the MAC valve) and the air bags start to deflate. The air loss out of the bags stops when I put the ignition switch in the off position and the Skinner valves lose their magnetized state and the MAC valves stop venting. When I start the engine (and ignition switch reverts to the on position) the Skinner valves become magnetized and the air continues to vent out of the same port on the two MAC (travel? [EDIT: down]) valves but the engine mounted compressor is able to overcome the air loss and the bags stay inflated. The compressor has to cycle frequently to keep up with the air loss. Supply PSI goes from 120 to 90 to 120 with the engine running. Once the engine and compressor are off, the supply pressure gauge on the dash drops to zero PSI in a few minutes but the air bags stay inflated.

What is going on here? Are those two MAC valves faulty for venting air when the ignition switch is on? What is the function of the Skinner valves? Do I probably have a significant air loss somewhere else? (I think that is likely.)