Air parking brake won't release
I have an 07 Thomas Saf T Liner (no wheel chair) with an Air parking brake and hydraulic brakes. The air parking brake won't release but the air pressure builds up just fine to 150 psi but I can hear and feel the back dumping air out of what I believe is a purge valve at the rear of the bus.
I've noticed that one of the rear brakes appears to be leaking brake fluid out of the bleeder screw, I don't know if this is related at all. I've checked the brake fluid and it was low but I have filled it.
Since this issue started happening I haven't been able to move the bus, except two random times where after letting it sit for an extended period of time, the parking brake will release immediately with no issue, but after turning the bus off and then starting it again the issue will return.