Impossible to find air leak

the cut out in my truck has been sticking open on occasion. if I turn the motor off it'll stop in seconds and not do it again for awhile. I think it leaks, I can't touch it so I took it a shop they say they couldn't find it

 

Do you have a dual needle gauge?

 

I've joined the club.... now mine leaks down to nothing overnight. Right to 0 suspension stays inflated. Cab air bags do not...

Replaced air dryer, tractor protection valve and cab air bags all with small leaks. This morning it was down to 40 lbs.. more work to do I guess.

 

on stand by

 

I found a bad leak in the dash once on our 379 Pete. That turned out to be the pressure switch.
Air bag leaks air dryer pop off valve not shutting fully and several other over the years. Once the engine fan had an air leak on it that was pretty bad.

 

Just a shot in the dark here....but check air hose in the cab that you use to blow your floorboards with... would be surprise how much air you will lose with the slightest leak from there. And not even know you have a leak

 

Use kids bubbles. My 84 Pete 359 is good for about a week and the air bags a month not running. I have my air horns shut off when not running cause I ve never been able to get the pull cord valve to stop leaking after buying a couple new ones.

 

Happy days...

Found my problems...

Truck stayed at over 100lbs for 72 hours

My check valves on both tanks weren't checking......allowing air to bleed back to places where there were multiple leaks..