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View Full Version : Drum Brakes Un-Adjusting Themselves?


Nosolace001
May 7th, 2015, 09:52
:wave:

I have a 2001 Cherokee in which I have installed an XJ Dana 44, all new drum parts, pads and drums. Ever since I installed the axle my brakes have been completely spongy for the first 1/2 of their travel and then suddenly engage and brake very well. I discovered this to be the rear drums WAY out of adjustment, almost all the way backed out. I adjusted the drums and the Jeep had excellent brakes... for three days, and now they are back to crap. I have done this twice now and can't figure out how the drums are un-adjusting themselves?!

Is the self-adjuster handed? Could I have installed the Driver's Adjuster on the Passenger and visa versa?

Thoughts?

TRCM
May 7th, 2015, 10:12
you could have.....do you use the hand parking brake ??

The only time the self adjuster really 'adjusts' is when the hand brake is used...not the normal brake pedal. The travel just isn't long enough with the pedal to move the adjuster cuz of how far away the shoe pivot point is compared to the hand brake.

The pedal pushes the top of both shoes out, thus engaging both shoes. The hand brake pulls the bottom of one shoe in to engage the top of that same shoe, and the balance bar up top, along with the adjuster at the bottom, also forces the bottom of the opposite shoe to engage. The extra travel needed for the hand brake to work is what also make the adjuster lever move more, and thus move the adjuster wheel more effectively.

I've always adjusted mine using the hand brake with the rear axle in the air

Nosolace001
May 7th, 2015, 10:18
you could have.....do you use the hand parking brake ??

The only time the self adjuster 'adjusts' is when the hand brake is used...not the normal brake pedal.

Yeah I do. I think they we're good for a few days because I was parking the Jeep in the garage, which is flat. Then I parked the jeep on my sloped driveway (using the parking brake) and after that the brakes were out of adjustment.

Does this mean that the self-adjusters ARE in fact handed?

Tim_MN
May 7th, 2015, 10:19
The brake self-adjuster is left side or right side specific. They are usually stamped L or R.

iwannadie
May 7th, 2015, 11:00
I would take a closer look at them, the adjuster cable can get messed up during the install really easy. Look really closely at the cable and the pivot guide and make sure they are how they should be. There should also be a stopper that keeps the adjuster from rotating the wrong way until the stopper is pushed out of the way. So if they are adjusting the wrong way that stopper is not doing its job.

Taking both drums off and looking inside and comparing one side to the other would be a good start I think.

TRCM
May 7th, 2015, 12:54
I would take a closer look at them, the adjuster cable can get messed up during the install really easy. Look really closely at the cable and the pivot guide and make sure they are how they should be. There should also be a stopper that keeps the adjuster from rotating the wrong way until the stopper is pushed out of the way. So if they are adjusting the wrong way that stopper is not doing its job.

Taking both drums off and looking inside and comparing one side to the other would be a good start I think.

You are correct....that 'stopper' as you call it tho, is also what moves the adjuster wheel when you use the parking brake.

If you have the adjusters swapped side to side, then when the stopper should be tightening the brakes, it will actually loosen them, since the adjusters are threaded backwards, and while the stopper moves the same way, the adjuster lengthens instead of shortening.

And taking both drums off and comparing, likely won't show anything, as you'd have to remove the adjuster wheel & adjuster to really see the difference.

8Mud
May 7th, 2015, 15:44
The adjusters being on the wrong side is the first thing that popped into my mind.

You may also want to look very closely at the adjuster cable pivots. They pop out of the hole often when installing the spring. They should be laying flat with no gap at all.

ehall
May 7th, 2015, 16:18
This is what it should look like

http://www.eric-a-hall.com/gallery/albums/cherokee-suspension/D35_Drum_Tensioner_Stock.sized.jpg

The black spring holds the pawl down. The adjuster wire loops over the ear on top and then clips to the top of the pawl. When the adjuster wire lifts up, the front of the pawl pushes up on the adjuster wheel, then skips back down into position (ratcheting action). It should do it everytime you back up and brake. If you never back up and brake in your daily routine, it will never automatically adjust.

thesteveyo
May 8th, 2015, 04:40
Thank you for the picture and explanation!

Nosolace001
May 8th, 2015, 09:56
Thanks everyone,

I am thinking they're most definitely installed on the wrong sides, I can't think of any other explanation. The stoppers are functioning because I have been pushing them out of the way to make the adjustment wheel turn easier.

Happy Friday! I should be able to take the time to look at them tonight

Hypoid
May 8th, 2015, 16:18
I am thinking they're most definitely installed on the wrong sides, I can't think of any other explanation. The stoppers are functioning because I have been pushing them out of the way to make the adjustment wheel turn easier. When you get the drums off, pull the cable to the side enough to make the pawl engage the star wheel. Cycle the pawl a few times and verify the adjuster is getting longer.

The only time the self adjuster really 'adjusts' is when the hand brake is used...not the normal brake pedal.I disagree with this statement. When I was tutored on drum brake adjustment, few U.S-made vehicles had hand brakes. The helpful tip shared with me was to get the vehicle going in reverse, and keep tapping the brake pedal. That was over three decades ago, and it still seems to work. :huh:

Next time I work on drum brakes, and actually start the vehicle while it is on jack stands, I'll have to see if your hand brake tip is more effective than my tried and true. :thumbup:

8Mud
May 8th, 2015, 17:30
When you get the drums off, pull the cable to the side enough to make the pawl engage the star wheel. Cycle the pawl a few times and verify the adjuster is getting longer.

I disagree with this statement. When I was tutored on drum brake adjustment, few U.S-made vehicles had hand brakes. The helpful tip shared with me was to get the vehicle going in reverse, and keep tapping the brake pedal. That was over three decades ago, and it still seems to work. :huh:

Next time I work on drum brakes, and actually start the vehicle while it is on jack stands, I'll have to see if your hand brake tip is more effective than my tried and true. :thumbup:

I use a combination of both, I apply the parking brake until it just grabs a little and then back up a few times and hit the brake pedal. It seems to adjust/tighten up my rears jiffy quick. Works even if the shoes are way loose from a new installation.

If you replaced the adjuster cables you may have gotten cables that were to long. There was a rash of these in the parts system for awhile.

TRCM
May 8th, 2015, 18:12
I disagree with this statement. When I was tutored on drum brake adjustment, few U.S-made vehicles had hand brakes. The helpful tip shared with me was to get the vehicle going in reverse, and keep tapping the brake pedal. That was over three decades ago, and it still seems to work.

Next time I work on drum brakes, and actually start the vehicle while it is on jack stands, I'll have to see if your hand brake tip is more effective than my tried and true. :thumbup:

What you are saying will work, but if you look at the pivot points and how much travel is needed to get the adjuster wheel to turn, the hand brake wins.

But a method that would likely work better is to do as the previous poster said, and engage the hand brake lightly, then bump the brakes while backing up.

All I know, is no vehicle I have ever owned has 'self adjusted' just from backing up, but every one has from using the hand brake.

ehall
May 8th, 2015, 18:22
If they work correctly, a forcful stop in reverse works good, you can even hear the ratcheting

TRCM
May 8th, 2015, 19:38
If they work correctly, a forcful stop in reverse works good, you can even hear the ratcheting

HUH ? if you hear ratcheting, something is wrong. Even the ratcheting you hear when you use the hand brake is not from the self adjustment, but is instead from the locking mechanism for the hand brake lever.

When you hit the brakes, the action of brake cylinder, shoes, pivot point, and adjuster cable will raise the adjusting lever once, and only once, for each push of the pedal, so there is no way for any ratcheting to occur, much less be heard.

The adjusting screw & socket are not spring loaded, and the only way they move or adjust, is by someone or something turning the star wheel. Either you with a spoon, or the adjusting lever when it is lifted by the action of the rest of the parts inside the drum.


The only way to get a ratcheting noise from the brakes is to turn the star wheel with the adjusting lever resting against it, and to do that, requires a brake spoon. Look at the pic posted above....if the adjusting lever is raised by either braking in reverse or by using the hand brake, it will move the star wheel 2 or 3 teeth at best, in 1 smooth motion, so no ratcheting occurs.

Now, if you use a brake spoon to rotate the star wheel, it will give a ratcheting noise as it overcomes the adjusting lever. Nothing can rotate the star wheel like that tho when you are braking.

ehall
May 8th, 2015, 20:01
HUH ? if you hear ratcheting, something is wrong. Even the ratcheting you hear when you use the hand brake is not from the self adjustment, but is instead from the locking mechanism for the hand brake lever.

When you hit the brakes, the action of brake cylinder, shoes, pivot point, and adjuster cable will raise the adjusting lever once, and only once, for each push of the pedal, so there is no way for any ratcheting to occur, much less be heard.
The pawl skips the teeth when it goes back down, aka ratcheting

TRCM
May 8th, 2015, 20:08
The pawl skips the teeth when it goes back down, aka ratcheting

You must have some mighty dang good ears then, cuz even using a spoon, I can't hear it laying under the jeep, as the teeth are angled down, so the adjusting lever rides over them smoothly.

The only 'ratcheting" I've ever heard is when the teeth of the star wheel are being forced the wrong way, as when you've adjusted the brakes too tight and have to loosen them.