Over the last week, I have noticed that both air gauges, primary and secondary, are dropping pressure from operating 125 PSI to 10 PSI, within 4 - 6 hours. I lifted the rear of the coach with the air bags and used the excellent 'Jon supplied' jack stands to support the rear of the coach, then crawled under to take a look. I used the venerable soapy water squirt bottle on the valves below the tanks, with no leaks. I doused numerous other fitting looking for leaks, but no joy.

But I kept hearing what sounds like air escaping in 10 second intervals (on of 1/2 second, then off for 10 seconds). I hear a slight leak (sort of like a squirt of air, then quite for 10 seconds. It sounds like the leak in internal, being it sounds like the air in being taken from the tank connected to the air dryer. I did not check to see if air was leaking from the air dryer discharge, but should have.

I wonder if a pressure relief regulator inside the air dryer is leaking? Very strange.

Has any others had symptoms such as these and what was the fix?

Hector