2007 M2 112 Emergency Brakes

[rspangle]

My emergency breaks do not seem to be working properly. With the emergency brake is applied, the truck will start to moved when power is applied from engine. Someone said I may have a broken spring in one or both of the rear air chamber and I should replace both. The front and rear air brakes work fine when using the brake pedal. I had the slack adjuster adjusted and this help, but there is still a problem. any advice would be appreciated.

Barkie

 

[davekc]

Not likely the chambers as they would both have to go out at the same time. Possible, but not that likely unless it is way out of adjustment. Should be automatic on a straight. Drive in reverse resets them when brakes are applied.
I would check the park valve itself. Including seals and the lines to it. If air pressure is still correct, I would then go to the brake modules which the m2 has I believe two or three of them.
If you can't identify the problem with those, I would get it to a competent shop.

 

[EASYTRADER]

To test e brake while slowly moving like 3 mph put truck in neutral and pop the yellow valve if the trucks stops the spring brakes are working if not you have issues.

The truck rolling when power is applied does not mean your spring breaks are bad it could mean you misunderstand breaks or I misread your post. Adding power against breaks is not how you test them it is how you can severly hurt your drive train. Try the above test if the truck stops with a lurch your good

Posted with my Droid EO Forum App

 

[BobWolf]

READ CAREFULY AS I ASSUME NO RESPONSIBILITY IF YOU OR ANYONE ELSE GETS HURT OR KILLED.... If this is outside of your comfort or mechanical level PLEASE take it to a shop.

It's fairly strait foward but you have to pay attention to the details.
First set your brakes, chock the wheels, and get out a flashlight mini mag lites work best as you can focus the beam A plain jane flashlight will work to just tougher to see
.
DO NOT TAKE ANYTHING APPART THIS IS EXTREMELY DANGEROUS look, listen, and feel only

First, Pop off the plastic caps for the hole that the cage bolts run through if they are there as they tend to fall off eventualy letting all the road crud into your chambers this will ruin your cans. take your time, look carefuly for broken springs or pices of metal or other debris. grab the cans and try to shake them make sure they are not loose.

If you dont see any broken springs or crud, hit the outside of the spring chamber hard all arround WITH YOUR HANDS!!!!! DO NOT USE A HAMMER!! listen for rattling if you hear rattleing, air leaking, see broken springs, or If they are filled with crud they're shot it's time to replace them. .

Next, a helper comes in handy. most of this can be done by yourself MAKE SURE YOUR WHEELS ARE CHOCKED and keep your hands away from anything moving.
Now apply air to the systeme, run the truck with the air applied to 120 psi.
Shut down the truck crawl under and listen for air leaks.
Shake the cans to be sure they are not loose.
listen arround the chambers, theyre should be no air leaks,

Next have a helper step on the brakes a couple times then release and apply air to the brakes look to make sure all slack adjusters are moving smoothly and evenly. watch the pushrod going into the ccamber if it stops and then sucks in you probly have a bad chamber or slack adjuster.

If giving the cams and ajusters a good lubing and adjustment dosent get it done get it to a shop.
If you live and work in the north / north east salt belt expect to get abbout one or so years out of your chambers.
Brakes are not the place to comrimise. Good Luck, let me know how it worksout.