[Express1]

Been working on Cannons 07, problem with 110 air. 
When we run engine to fill all supply tanks. Then shut down, the 110 compressors don't run for nearly 20 minutes. 
After that, they start every 3 minutes . 
No obvious leak, yes we have repaired 12-15 small leaks.
We have closed all regulators found, including slides and toilet, also the genny air bags!
It doesn't matter what we select in the leveling system, it will hold position for 12-18 hrs.
Possible check valve allowing aux. tank to bleed into main tanks?
We are at stand still. 
Not finding obvious leak??? 
Any ideas please!
,

[bikestuff]

Have you verified that you are really losing air? The little thingy that turns on the compressors may be out of adjustment. How long do the compressors run when they turn on? On mine, there is an upper and lower threshold for the compressors to run. I don't remember exactly but think they come on at 50 lbs and turn off at 90.

[rheavn]

Matt,
Bill's advice is good.  

Start the coach & air up with the 110V air compressor off.  When air system is full shut off the engine.  Monitor & record readings from both needles of the brake gauge and the auxiliary air gauge (supply).  Record how long it takes your auxiliary air gauge to drop 10 psi from full all the way down to zero.  When your auxiliary  gauge hits zero what do the needles of the brake gauge read?  Report back the results.

With the engine off, turn on the 110V air compressor, record at what the auxiliary air pressure gauge reads when the 120V air compressor starts and shuts off.  Also time how long the 120V air compressor runs between starting & stopping.  Report back the results.

Have you built a leak down tester to determine whether the components you cited are leaking? A leak down tester is the only tool that will 100% positive tell you whether or not the component is leaking AND allow you to measure the amount it is leaking.