Park brakes won't release on a 1992 Eagle

[The Wright Bus]

After having been parked for a couple of months, I drove my 1992 Eagle for about 30 minutes. When I returned home I set the brakes to unload my family. After unloading, the brakes wouldn't release and I have been unable to move the bus since. The air builds up fine (between 120 and 130 lbs) but depressing the park brake and then the brake pedal has no affect.
Any suggestions would be greatly appreciated.
Thanks,
Bernard

[buswarrior]

Hello Bernard.

Which parking brake set-up does your Eagle have? Spring or DD3?

Assuming that all tanks have air, and you do not have it leaking out somewhere, and you aren't writing from some frozen place after driving through a puddle...

My first guess is you were lucky it released to go for the drive, the internals of some valving are sticking or have broken, preventing the air from doing what you ask.

let us know some more as to symptoms and where you are sure there is air and where it isn't according to control positions.

happy coaching!
buswarrior

[jhaggerty]

Had a similar probem on my MC 9. It turned out that the foot valve was not releasing all the way up when you removed your foot from the pedal. I just reached down and pulled it up with my hand and away it went. It doesn't take much to keep the brakes on! I  hope it is that simple.

Jim

[YeomansEagle]

Jhaggerty is right on. I have an 85 model 10 eagle same problem. Spayed a little wd40 on the valve & it has worked perfect ever since. This happened about 6 months ago. There may be other problems but I would check this one first.

[phil4501]

Probably different than your eagle but I had the same problem with my scenicruiser and I disassembled the rapid release valve and cut out a new diaphram out of neoprene, then reassembled. works perfect now.

Phil Zisakis

[NJT 5573]

Bernard, You have a park brake lite, Is it on or off? If it goes off after you hold the pedal down for 30 seconds, put the bus in reverse and put some torque on it, just a stuck shoe. You also have a reserve tank of air that is connected to a valve at the drivers seat, it usually is covered with a flip box etc and usually has a green handle. It is for emergency release of the brakes and bypasses the system. If it releases the brakes, you have a valve problem. If it does not release the brakes you have a stuck shoe, (common) or a blown air can @ one of the drivers. Easy to check, just have someone hold the brake on and listen for escaping air. Easy to fix, but don't take an air can loose until you know the procedure as the spring will take your head off if you do it wrong.