Adjusting brakes. Basic question re: how to?
 

Adjusting brakes. Basic question re: how to?

Started by zubzub, December 03, 2007, 06:05:27 PM

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zubzub

In my manual it says to adjust the brake by turning the worm gear until it makes the pads bind and then backing it off X # of turns.  Is this how you all do this?  Seems pretty difficult for routine maintenance, requires lifting the bus by the axcle etc...  I figured probably just adjust for the 90 deg., off the pot.  But as usual I am looking for more info.  Patrick.

TomCat

I have leaf over straight axle front and rear, and just slide under when it's time to adjust. I usually adjust/lube my brakes before every trip, and may adjust them on the road if I don't like the feel and performance.

Jay
87 SaftLiner
On The High Plains of Colorado

Tom Y

Patrick, Thats the way. Jack just enough to spin the tire and block under the rubber stop for safety. The fronts should have close to the same travel to pass DOT. No more than a 1/2 inch? I am not sure. My back has auto adjusters but the front are not. Push ring around bolt head in and adjust with wrench. Hope this helps.   Tom Y
Tom Yaegle

gomer

when adjusting mine I have always tightned them up and then backed them off 1/4  turn and they work just fine.  IMPORTANT you will have to adjust the parking brake with them not on.  SCOTCH THE WHEELS AND BLOCK THE COACH UP TO KEEP IT FROM DROPPING ON YOU AND YOU WILL GET HURT IF NOT KILLED>  WE HAVE LOST SOME OF THE BEST NUTS JUST THIS YEAR BECAUSE OF NOT BLOCKING THERE COACH>  If you have an eagle,no problem but scotch it solid. blocking it is always a good rule tho for any coach.  Mci,Prevost have air ride,  IT isn't hard to do just do it SAFELY...

Gomer
as you slid down the banister of life,may the splnters point the other way
TRUST IN GOD ALWAYS. riverjordanmusic@aim.com
Gomer

Don4107

Patrick,

I would suggest you rent a pro for an hour or so.  Does not matter if it is a shop or an independent as long as they meet two criteria. 1. They know what they are doing.  2. They are willing to teach you.  A pit is a big plus so you can really see whats up.  You need to learn what and how to inspect, lube, and how to adjust and road test at a minimum.  There is more to it than 'tighten them up and back off 1/4 turn'.  Will be some of the best money you spend on peace of mind.

As a side benefit you will find out if the PO left you with serviceable brakes or if you need repair rather than adjustment.

Good luck and happy braking.  ::)
Don 4107 Eastern Washington
1975 MCI 5B
1966 GM PD 4107 for sale
1968 GMC Carpenter

TomC

I adjust mine about once a year.  You could have automatic slack adjusters installed like all trucks have now, but it is nice to be forced under the bus to take a look. 
Tighten down the slack adjuster till stop then back off 1/4 to 1/2 turn-bang the brake drum with the wrench to make sure it rings like a bell-then you know the brakes are not dragging.  Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Dreamscape

I have to agree with TomC and others.

This was done as a show and tell at TBR 2007. Sonnie crawled under Darrin's Eagle and really didn't look that difficult. I watched, as I have not done that yet, and was the gopher! I must admit that I'm embarassed that I have not done such an easy task.  :-[ I will before I take her out next spring for sure. Of course this was on an Eagle, on coaches with air bags you would need to block up the coach and most important be very safe.

Paul

buswarrior

Hello.

Please, please, please, MEASURE your applied push rod stroke after you have tried to adjust the brakes using the above mentioned tricks.

The measurements required for your size of brake chambers are found in the commercial regulations.

There is more to stopping than setting the linings. The probability of brake cam wear is high in our buses, as the commercial operator was planning to dump our ride, and would not have done fresh brake work just to sell the coach.

Worn cams let the mechanicals twist, using up your limited stroke, and can lead to the brake linings not being squeezed as tightly as expected.

A short push rod stroke, with confirmed lining free play, assures you that many other underlying brake issues are good.

happy coaching!
buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

Utahclaimjumper

You should also check your manual (you have one don't you??) and know how thick the shoes should be. My 4106 manual says 3/4 inch thick new and 3/8 inch min. They are also available in over thick sizes.>>>Dan
Utclmjmpr  (rufcmpn)
EX 4106 (presently SOB)
Cedar City, Ut.
72 VW Baja towed

Dallas

There are now markers on your brake lining that show minimum thickness so you don't have to get a caliper in there to try and measure it.

Look at the side of you brake lining and you'll see a line about half way down the side that runs from end to end. That is the minimum thickness line, beyond which it's time to replace.

If you can't see the line because of grease /dirt, start looking for a leaking grease seal.


IHTH

Dallas

kd5kfl


zubzub

Thanks everyone.   I guess I got it right then.  I'm just concerned with dragging brakes as my handbrake fire has left me a little wary.  Seems if a brake was dragging, it would create heat, but i guess with an outside drum this would help ease the drag.  I found out the hard way that the inside drum of the handbrake expands when the barke drags and then the brake drags more ! Thanks as always for the input.  I especially like the ring the drum tip.  Patrick

buswarrior

Hello.

Some things to consider:

Many busnuts do little mileage every year, so need little in the way of brake adjustment.

Many busnuts are prone to being lazy with wheel end maintenance.

Two birds with one stone:

Take a day once a year, jack up each corner, pull the wheels off, grease and inspect everything, and set the brakes as snug to free rolling as you can with the wheels off the ground.

"Winging it" on the ground doesn't cut it anymore. The manufacturers all recommend, as best practice, to raise the wheel to ensure free running, and so you back off the brake as little as needed for free running.

Adjusting the brakes on the ground doesn't let you know they are running free, and won't expose out of round drums, hanging shoes, broken return springs...

A dragging brake has the potential to set your rig on fire.

Leaving the wheels on for years at a time makes it difficult or impossible to remove them.

Not inspecting or greasing the wheel end annually leaves you open to all manner of expensive problems or unreliable performance.

So...

Practice makes perfect...

Get the kids/grandkids/neighbour's kids to do the heavy work, but get deep into your wheel ends once a year!

happy coaching!
buswarrior

Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

zubzub

Sounds good to me.  I have always been a big believer in PM.  Also when I do PM I always notice other little things that need doing/monitoring.