air brakes wont relese

[Jim Hutchings]

You may have a ruptured diaphragm on one of the rear brake units. The rear
brakes are your parking brakes and are engaged by a spring. If the air
diaphragm that counteracts the spring has a hole in it the brake shoes will not
release. Pressure up the air system and shut off the engine. Chock the tires
for safety and have someone else push in the brake release. If you hear air
leaking out of either side of the rear brakes you most likely lost a diaphragm
or air hose. There is a way to manually release the spring brakes by backing
out a very long bolt on the brake can, but you must be sure to do it safely.
See forum post about working under air bag supported busses. Also I doubt that
dumping your suspension has anything to do with the brakes since you are getting
a full load of air. You can change out a diaphragm yourself, but if you are not
familiar with it would suggest you get some help.

Good luck and be careful,

Jim Hutchings
1982 FCRB
Yorba Linda, ca


From: WanderlodgeForum@yahoogroups.com [mailto:WanderlodgeForum@yahoogroups.com]
On Behalf Of Robert & Teri Rahn
Sent: Tuesday, October 30, 2007 3:49 PM
To: WanderlodgeForum@yahoogroups.com
Subject: [WanderlodgeForum] air brakes wont relese


I just went to get my bus from its parking spot to bring it nearer to
my shop to attempt replacing the water heater and the air brakes wont
let me move it. When I push in the button after waiting for the
pressure to get up to 120 the brakes stay engaged and the air pressure
starts dropping steadilly untill I pull the button back out. I have
never worked on the air brakes, what is the method for relesing them? I
have the air suspension dumped, does that matter? I have it in a
building that I just built and had to dump it to get it in because the
ground is not level and with it up it almost hits the posts supporting
the building.

Robert Rahn
Kalispell, Mt.
1988 pt 40



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