Adjusting front brakes.
 

Adjusting front brakes.

Started by johns4104s, April 07, 2009, 04:43:25 PM

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johns4104s



Is there a need to have the bus air up, say to 100 plus lbs to adjust the front brakes?

Thanks

John

LarryN 4106

If your 04 has slack adjusters like my 06, then all the air does is lift the bus up so you can do the adjustment. Be careful when working under the bus. I jack each wheel up so it will turn. Others may just use a hammer and listen to the drums "ring" with the bus on the ground all around.

busshawg

I always set my brakes up with the brakes released, therefore yes you would need air to keep them released.  I usually don't set my brakes up quite as tight up front as I do on the back.
Have Fun!!
Grant

LarryN 4106

Quote from: busshawg on April 08, 2009, 09:15:03 AM
I always set my brakes up with the brakes released, therefore yes you would need air to keep them released.  I usually don't set my brakes up quite as tight up front as I do on the back.

Grant, while I am not familiar with an MC5, why would your front brakes not be released without air? (Inquiring minds, etc.....)

JackConrad

If you are adjusting your front brakes, shouldn't you also be adjusting your rear brakes? Adjusting the rear brakes will require releasing the parking brake (which will require air pressure). Also, do not do this without blocking the bus before crawling under it.  Jack
Growing Older Is Mandatory, Growing Up Is Optional
Arcadia, Florida, When we are home
http://s682.photobucket.com/albums/vv186/OBS-JC/

TomC

Adjusting the rear brakes requires air built up to release the parking brakes fully.  The front brakes don't need such treatment since they do not have parking brakes.  I can adjust my fronts without getting under the bus by just cranking the wheel right to work on the right side and crank it left to work on the left side through the wheel well.  If most don't know, to adjust the brakes, first grease the fittings (makes things easier), wipe off the dirt around the collar of the adjuster nut, then with a 9/16" closed end wrench, push in the collar and tighten down the adjuster nut until you feel resistance (doesn't have to be tight).  Then back off by 1/3 to 1/2 of a turn and it should be adjusted properly (make sure the locking collar pops back out again to lock the adjuster nut in place).  This should be done at least every 5,000 miles-more if in mountains or doing alot of stop and starting.  On my big rig truck, I had self adjusters installed and it eliminated crawling under to adjust the brakes-one of the best purchases I made.  Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

buswarrior

And the last step of adjusting the brakes, that is always left out...

Measure the applied pushrod stroke, being sure that you didn't back off the adjuster too far, or that you loosened it off instead of tightening it. You will also expose underlying defects that you would really prefer to know about the easy way!

There is no rule for right or left turning to adjust, it depends on the orientation of the install, and don't think that brakes haven't been loosened all the way off by mistake....

For the stroke, somewhere around an inch give or take is great, then you need a chart to refer to for the safe/compliant stroke for the size of brake chamber involved.

If you can't get the shoes away from the drum without having a long stroke, you have worn or broken parts that need to be freshened up.

The condition of the S-cam camshafts are a noteworthy item that is at risk of being worn and wobbly in our cast-off coaches. The wobble wastes valuable pushrod travel, taking up the slack of its movement in directions that are not producing brake force.

Better still, take a course!

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

Fredward

I believe the MCI manual for the MC-5 says maximum throw of 1-3/4". If I recall. I will echo that the S cams may need replacing. Also there are bushings that the S cam shaft runs in that can become worn and affect the operation of the shoes.
Fred
Fred Thomson

Don4107

And the first step after adjusting brakes is to drive it a few miles and check the drums for temp.  To hot, to tight.

Don 4107
Don 4107 Eastern Washington
1975 MCI 5B
1966 GM PD 4107 for sale
1968 GMC Carpenter

Tony LEE

"and don't think that brakes haven't been loosened all the way off by mistake...."

Yes indeed. The last safety check showed drive axle brakes were not equal so I called in at the usual workshop on the way home. (had to get an approved shop to clear the defect) He left the engine running to keep the air up to keep the bus up and slid underneath - yeah, the daredevil type, but I guess I shouldn't complain because it is cheaper not to have to do things safely.

5 minutes and I was "good to go".  Got out on a deserted road and tested the brakes. Before the adjustment, I couldn't tell there was a problem. After the adjustment there WAS a problem. Drove it home and checked - yes, he had screwed one side the wrong way and there was no braking at all.

zubzub

Sounds like buddy was trying to win the Darwin award for you and him. :)