Bus Conversions dot Com Bulletin Board
October 31, 2014, 12:59:50 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: 500 Members as of May 5th, 2006.  Smiley  3,499 Members as of October 21, 2012 Cheesy

   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: [1]   Go Down
  Print  
Author Topic: Why do my brakes chatter when backing up?  (Read 1595 times)
belfert
Hero Member
*****
Offline Offline

Posts: 5448




Ignore
« on: December 02, 2012, 09:47:38 AM »

My front brakes chatter when braking while backing up.  The noise is pretty bad.  The brakes work just fine when braking in the forward direction with no noises?  Any ideas here?
Logged

Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN
dbenck
Jr. Member
**
Offline Offline

Posts: 55





Ignore
« Reply #1 on: December 02, 2012, 12:42:27 PM »

My shoe brakes do this if they sit and get rust on them. Driving foward and good brake applications clears it up.
David
Logged
belfert
Hero Member
*****
Offline Offline

Posts: 5448




Ignore
« Reply #2 on: December 02, 2012, 02:09:48 PM »

I wonder why this would start happening now?  I believe it happens even after a trip of some miles.  I can't recall if it did it when I backed into my driveway after getting home from my 4,000 mile trip.

I think I'll take the bus out for some driving on city streets next weekend if it stays nice and see if it clears up after a number of stops.  It has hardly rained at all here since I got back from my trip so I don't see how they would rust too badly, but even my car brakes will sometimes squeal a bit after just sitting overnight.
Logged

Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN
luvrbus
Hero Member
*****
Offline Offline

Posts: 12802




Ignore
« Reply #3 on: December 02, 2012, 02:21:19 PM »

Brake shoes develop a wear pattern in the forward braking a little rust and moisture just about all buses will chatter in reverse after setting for a couple of weeks, out of adjustment brakes the more the chatter, did not your Bendix instructor in Bendix class you were in not cover that ?
« Last Edit: December 02, 2012, 02:40:32 PM by luvrbus » Logged

Life is short drink the good wine first
chessie4905
Hero Member
*****
Offline Offline

Posts: 739





Ignore
« Reply #4 on: December 02, 2012, 05:09:39 PM »

part of the shoe must be dragging on part of the uneven surface of drum. If they aren't touching the drum, they aren't going to chatter. Take drums off and check for uneven wear on drums and shoes and grease or oil on linings or drum surface. Maybe your brake system is different than most coaches?
« Last Edit: December 02, 2012, 05:11:19 PM by chessie4905 » Logged

GMC h8h 649#028
Pennsylvania-central
belfert
Hero Member
*****
Offline Offline

Posts: 5448




Ignore
« Reply #5 on: December 02, 2012, 05:46:52 PM »

Brake shoes develop a wear pattern in the forward braking a little rust and moisture just about all buses will chatter in reverse after setting for a couple of weeks, out of adjustment brakes the more the chatter, did not your Bendix instructor in Bendix class you were in not cover that ?

The Bendix instructor didn't cover much about wheel end stuff.  I don't recall anything about chatter, but I don't remember everything from class either.

As to Chessie4905's point, this happens only when actually using the brakes.  Dina uses a fairly standard Q brake system.  Pulling any drums will have to wait until the weather warms up.
Logged

Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN
luvrbus
Hero Member
*****
Offline Offline

Posts: 12802




Ignore
« Reply #6 on: December 02, 2012, 05:58:33 PM »

All good bus brake shops will turn a new drum so the shoe will run inwards instead of outwards inside the drum (per Meritor/Rockwell and Webb) that will cause chatter after setting for long periods when backing up

 I would not worry about if you have had new drums installed in the last few years at a good shop


good luck
« Last Edit: December 02, 2012, 06:04:11 PM by luvrbus » Logged

Life is short drink the good wine first
wg4t50
Hero Member
*****
Offline Offline

Posts: 806





Ignore
« Reply #7 on: December 02, 2012, 06:33:02 PM »

Good time to check and adjust slack adjusters ..
Dave
Logged

MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for over 50 wpm for ever.
Central Virginia
hargreaves
1987 MCI 102A3
Sr. Member
****
Offline Offline

Posts: 299





Ignore
« Reply #8 on: December 02, 2012, 07:30:54 PM »

Our city buses squeel at times, sometimes unbearably loud. We have a spot in the yard where we back up at about 10 miles per hr. and jam on the brakes. They would chatter and howl and deposit all the dirt and grunge on the ground from the front suspension. We did this about 3 or 4 times and the chatter would go away and the squeeling in forward would be gone.  As Clifford says they build up a pattern on the shoes and also some glaze. this process removes it.    Cheers   Gerry
Logged

now as of Feb 2012 series 50 B400  . Sunshine Coast British Columbia
gumpy
Some Assembly Required
Hero Member
*****
Offline Offline

Posts: 3274


Slightly modified 1982 MC9


WWW

Ignore
« Reply #9 on: December 04, 2012, 02:37:28 PM »

one side on mine does it every time I back out of the driveway after sitting for several weeks. It's caused by a film rust on the drum surface, and potentially slightly out of adjustment. It clears up immediately when I run it forward and apply the brakes. Only happens when the bus has been sitting for long periods of time.

Check your adjustment and don't worry about it. Just apply more brake the first time you use them backing up after sitting for a long time.
Logged

Craig Shepard
Located in Minnesquito

http://bus.gumpydog.com - "Some Assembly Required"
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!