Does 20PSI ring any bells?

[Pjanecke]

Originally Posted by rrueckwald

In mine the major leaks were the PPV at the bulk oil fill, which I removed from the bus entirely, and a "T" in the air horn lines in the cabinet above the passenger windshield. There were lots of little leaks, but I replaced every cheap air fitting with DOT fittings and that did the trick. It's like an Easter Egg Hunt....

When I went looking for air horn leaks I didn’t expect 3/8” tubing - that’s a lot of potential air leak!
3 overhead locations with multiple leaky push fittings in each:
1. Center cabinet behind DVD player etc: a leaking tee
2. Behind curbside ac gauge panel: leaking tee and a leaking push fitting on the low horn solenoid valve and on a 1/4” solenoid (purpose unknown, line heads down toward top of entry door)
3. Behind generator panel above drivers head: a leaking push fitting on the high pitch horn solenoid valve.

With those fixed my aux compressor can air the coach up from zero to 125.
Still leaks down over an hour period, but BIG improvement!