Thread Tools Display Modes
Old 10-03-2012, 07:42 AM   #1
New Member
Join Date: Sep 2011
Posts: 2
Year: 1992
Coachwork: Thomas
Engine: 5.9 Cummins
Air Brake Help

Ok got the bus out of storage, brakes were definitely froze. I would press them and the bus would come to a jarring halt and throw you out of the seat almost. Got it home and lubed up the brake components to best of ability. Took it out for a spin and it is a lot better, but when you press the pedal, about half the time it stays activated and will not release brakes (unless you mash it real hard to release them). Took the main valve off of the firewall in engine compartment (the one that sends air either in or out to chamber) hoping thats the problem.

Any other thoughts?


Buckeye0812 is offline   Reply With Quote
Old 10-03-2012, 10:53 AM   #2
Site Team
crazycal's Avatar
Join Date: Feb 2007
Posts: 4,075
Re: Air Brake Help

If you did what I think you did, you have activated your brakes. You need air pressure to release your brakes. You can't think of air brakes like hydraulic brakes on your car. When you step on the brake, you are releasing pressure which applies the shoes. I would have your brakes checked out by a mechanic that understands air brakes, not you local mechanic. You might also read up an air brake manual in the DMV commercial driver handbook to give you an overview of the brake system.
I'm hungry!

You Gotta Let Me Fly
crazycal is offline   Reply With Quote
Old 10-03-2012, 01:45 PM   #3
Site Team
crazycal's Avatar
Join Date: Feb 2007
Posts: 4,075
Re: Air Brake Help

Oops. Maybe I should be doing the reading. I think I'll watch the video.
I'm hungry!

You Gotta Let Me Fly
crazycal is offline   Reply With Quote
Old 10-26-2012, 02:18 PM   #4
Bus Nut
browncrown's Avatar
Join Date: Apr 2008
Location: Bakersfield, California
Posts: 969
Year: 1976
Coachwork: Crown
Chassis: Supercoach
Engine: DD Inline 6-71 MidShip
Rated Cap: 79
Re: Air Brake Help

Sounds like the service brake valve (the one from the brake pedal) may be sticking open. Think of the air system like a water faucet. There is water going to a faucet all the time, but unless you turn it on, no water. The air system works the same way. Air pressure is always there on one side of the system, but none on the other until you press the pedal. The only two ways to deliver air to the brakes is to open the service brake valve by steeping on the pedal, or releasing the PP1 valve (Spring Brake) to set the rear brakes. You mentioned you took the main valve off to check, and that is the most likely source of the problem. It has a diaphram inside, and if not closing properly, could be your problem. Its sounds like your looking in the right place.
My Conversion Thread:
browncrown is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
air brake 101...or how to fix/diagnois a stuck brake issue bansil Conversion General Discussions 16 06-28-2012 02:28 PM
Air Brake Help??? talk2cfs Ford Drivetrain 1 07-31-2010 07:12 PM
Brake Help!!! quizbus Conversion General Discussions 4 07-15-2008 08:37 PM
two air brake tanks? adamanderr Conversion General Discussions 9 02-03-2008 11:06 PM
Brake Problems, need help captainkf Conversion General Discussions 4 09-23-2007 12:23 PM

» Virginia Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 06:54 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2016, vBulletin Solutions, Inc.