LXI Accessary system air leaks

[cvaughn]

I have an air leak in my acc. system. The chassis will hold 130 psi for weeks. The toilet circuit will hold air for two hours. The acc. circuit will hold for 20 minutes. To date I have added an extra check valve in the supply line as the 120v compressor was leaking. I assume the factory check valve has failed. I stopped leaks at the bulk head where supply goes to the acc. tank. I have removed and plugged the plumbing at the air over oil pump in the engine bay. All fittings at the dump panel have been tightened, no leaks. All three cylinders, two dump & one step appear to be holding. i.e. no air out the top or out of the unpressurized port when the hose is removed in normally closed sewer valve or normally open step cylinder. No leaks out of the electric over air solenoid under the step. All leveling valves have been removed as I use an HWH leveling system. Does anyone have any thoughts on where else to look?