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#1 |
Registered User
Join Date: Jul 2012
Location: Fort Worth, Tx
Posts: 3
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Rear Drum Brakes Grabbing
Here is the deal, I have new fron Disc brakes, New master cylinder and Booster, New Rear Brake Shoes and slave cylinders on both. They all bleed and flow easily, Long linings in rear and shorts in front of both sides, correct adjusters on the correct sides, however on my passenger side after a while driving and it self adjusting only that side get to tight and starts grabbing or I should say braking. Make me feel like I'm towing the qween mary. Put it up on lift and can turn it by hand in reverse but not forward. I have also welded up the six rub pads on the backing plates and resurfaced then as they did have bad grooves. Emergency cables have been disconnected and or loosened with no changes. With Drum off the axle moves freely so bearing is good and there are no leakes. Drums have been checked for out of round and are good. All Springs are new and in great shape. What else is there?
Has anyone ever got a bad set of shoes, or does anyone else have any ideas? |
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#2 |
Who Me?
Join Date: Sep 2010
Location: Royal Palm Beach, FL
Posts: 4,067
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Re: Rear Drum Brakes Grabbing
Is this the way it was before you replaced all the brake parts in the rear? Meaning no change? If you back off the self adjuster and drive a while, does it tighten back up?
I would not think its a shoe issue, but maybe its a fluid flow issue, not returning to the MC. I have had rubber brake lines on the front collapse and would not allow fluid to return to the MC.. The rear is all steel lines except for the one flex line.. I would also look at replacing that flex line in the rear too.
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![]() 1997 Tahoe LT 4D 2WD (DD) 2001 Blazer 4D 2WD 1961 Apache 10 (sold) 1965 C10 Stepper (sold) |
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#3 |
Junior Member
Join Date: Feb 2005
Location: topeka, kansas
Posts: 258
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Re: Rear Drum Brakes Grabbing
You sure that self-adjuster is not in backward on that side that is grabbing?
Here's the way it should look. http://repairguide.autozone.com/znet...3f8020d779.gif
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#4 |
Who Me?
Join Date: Sep 2010
Location: Royal Palm Beach, FL
Posts: 4,067
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Re: Rear Drum Brakes Grabbing
I was wondering that too.
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![]() 1997 Tahoe LT 4D 2WD (DD) 2001 Blazer 4D 2WD 1961 Apache 10 (sold) 1965 C10 Stepper (sold) |
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#5 | |
Registered User
Join Date: Feb 2009
Location: southeasternfoothillsofusa
Posts: 1,557
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![]() Quote:
You could swap sides w/shoes & try it if you suspect bad shoes--that should make problem switch sides. If all else fails, one could always alter the system to "render the adjusters inoperative"--I never suggested to remove the self-adj. system, did I? Sam Last edited by luvbowties; 01-22-2013 at 07:21 PM. Reason: another suggestion |
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#6 |
Registered User
Join Date: Feb 2009
Location: southeasternfoothillsofusa
Posts: 1,557
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After further thinking, I agree with what others have said: it does not sound like a shoe problem, but more like fluid-flow. Next time it tightens up, see if opening the bleed screw frees up that wheel. (then try loosening the line at the cylinder; then loosen the line at the tee.) If this frees it up, it's either a bad wheel cylinder or the fluid line from the cylinder to the "tee". If it was a bad flex line, both wheels would tighten up.
Sam |
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#7 |
Registered User
Join Date: Nov 2008
Location: Lacombe, LA
Posts: 2,772
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Re: Rear Drum Brakes Grabbing
As stupid as this may sound, I put the rear shoes on backward and they grabbed jusy like you saying. I learned that one shoe is a touch longer than the other and needs to go on in the correct location.
You sure you got that one correct?
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#8 |
Registered User
Join Date: Feb 2009
Location: southeasternfoothillsofusa
Posts: 1,557
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Here I am thinking out loud again. There should be no way a self-adjuster could adjust too tightly........unless something like the drum being too thin, expands when hot, and the adjuster tightening the shoe while the drum is expanded; then, when drum cools off, the shoe will be too tight.
Check the e-brake bars to ensure they are seated in the correct slots of the shoes, esp. the one on the good(driver's) side. Please, could you post a pic of each side with the drum off? We all should be able to offer more informed opinions as well as answer ???? you have already answered. Plus, we will feel more comfy that your descriptions are accurate and that your pics look like ours do when our systems are working correctly. Sam |
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#9 | |
Registered User
Join Date: Jul 2012
Location: Fort Worth, Tx
Posts: 3
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Re: Rear Drum Brakes Grabbing
Quote:
It seems like the slave cylinders ar not good but they have now been replaced with brand new ones, and I checked the new ones for smooth operation. When I take the drums off the shoes arn't fully returned and seated on the top capstand pivot point. But like I said the springs are all new and the shoe rub points on the backing plate are smooth and greased lightly with lithium. I do brakes all the time but this one has me stumped. |
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#10 | |
Registered User
Join Date: Feb 2009
Location: southeasternfoothillsofusa
Posts: 1,557
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![]() Quote:
Are you sure driver side shoes have returned to capstan pivot and seated, when the pass side have not? (5)NOW, If both sides are unseated and not returned to pivot point, then a bad flex line could be the culprit--even tho' the driver side has not self-adjusted up tight yet, right? (This could be just that pass side has heated faster due to shoes rubbing on drum a tad earlier and locking pass shoe up FIRST due to 'shoes dragging' more or sooner than on driver side.) We still would like to see pics with drums removed. Remember, we all love pictures on this forum. ![]() Looking forward to seeing this one through. Don't forget: I too now have a lot(of time) invested; so I feel deserved to being kept aware of the progress--good AND not-so-good--as well as the final solution. ...and now your partner! ![]() Sam |
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#11 |
Registered User
Join Date: Sep 2006
Location: Louisiana
Posts: 374
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Re: Rear Drum Brakes Grabbing
Did you change the master cylinder with your disc conversion up front? I believe that master cylinder for discs use a check valve to keep pressure on the calipers vs. drums which do not use the check valve. Would be interested if you have a master cylinder that is for discs all the way around vs. disc on front drums on the back?
Regards, Steve |
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#12 | |
Registered User
Join Date: Aug 2006
Location: Athens, Georgia
Posts: 1,456
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Re: Rear Drum Brakes Grabbing
Quote:
I did it on my Suburban, and didn't figure it out for months. And thousands of miles. The shoes would grab and drag, the brake fluid would get hot, and pretty soon I'd have a rock-hard pedal. I'd pull over, bust out the tools, un-screw the self-adjuster in a parking lot, and go until the self-adjuster tightened the shoes up again, a few hundred miles or several weeks later, depending on how much I backed up in that time (activating the self-adjuster). Once I realized what an idiot I was, that particular problem was solved. -Brad
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brakes, grabbing, locking, sticking |
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