This bus went thru inspection and the tank check valves would not hold . The primary and secondary tanks would lose air when one was bled down . Took 6 times to get them too hold . So I am trying to figure where the check valves are located . I have never had bad check valves so this kind of new for me . Also our stop paddle is really slow coming out . Is there a regulater valve and if so location in bus
Sounds like a double check valve. If like my newer buses, not Thomas buses, the old style double check valves have now been replaced. They are now built into the parking brake valve(PP-1). Now it is a PP-DC, if I remember correctly.
On my HDX's those valves are mounted to the first crossmember above the front bumper. The forward one has the low air switches and the rearward one has the brake switch on it, and sorta hidden about wiring harness.
Not familiar with the air systems but the stop arm pressure regulator on the C2 is located behind the removable kick panel next to the driver's left foot
the check valve is mounted in the front of tank 1 or primary if the stickers are intact. it looks like a 90* fitting it's the only line running to tank 2 or secondary. part number is BW K112234