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Old 06-22-2013, 08:14 AM   #1
six8burban
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Rear brake seizing..... help!

What's the common reason my rear drums would lock up? Lock-up as it feels like I'm driving with emergency brake on. It was hard to rotate rear tires while off the ground. I first disconnected e brake cable wich didn't help. Only by opening driver side bleeder valve releaseing a litile fluid out solved the problem. I took the same 3 mile test drive back home and felt it starting to seize up as I got into drive way. I'm thinking the problem is from exhaust heat or wheel rotation? Stainless steel brake lines have about 1 inch clearence from headers as it passes frame rail from proportion vavle. In the past i have let the truck idle for about 30 min before atempting a test drive. I have front disc brakes stock rear drums with internal rebuild kit.......entire brake system is new except emergency brake cable and brake pedal. 68 suburban only have about 6 miles since rebuild.
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Old 06-22-2013, 08:45 AM   #2
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Re: Rear brake seizing..... help!

Rear shoes adjusted too tight ???
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Old 06-22-2013, 08:47 AM   #3
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Re: Rear brake seizing..... help!

its always best to run brake lines as far from heat as possible...but I don't think that's your current problem...heat will boil the fluid resulting in no pedal...even if it were expanding it would just flow back into reservoir...unbolt master from booster when it happens,i think pushrod is too long
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Old 06-22-2013, 09:01 AM   #4
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Re: Rear brake seizing..... help!

X2 on the pushrod clearance problem
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Old 06-22-2013, 09:38 AM   #5
six8burban
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Re: Rear brake seizing..... help!

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Originally Posted by volksworld View Post
its always best to run brake lines as far from heat as possible...but I don't think that's your current problem...heat will boil the fluid resulting in no pedal...even if it were expanding it would just flow back into reservoir...unbolt master from booster when it happens,i think pushrod is too long
Ok petal was hard before starting and soften up when vehicle was started What's the proper length for a push rod? How should I measure.....I don't want to cut it too short?
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Old 06-22-2013, 09:39 AM   #6
six8burban
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Re: Rear brake seizing..... help!

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Originally Posted by vidman View Post
Rear shoes adjusted too tight ???
Ill check, just loosen a little?
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Old 06-22-2013, 09:56 AM   #7
volksworld
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Re: Rear brake seizing..... help!

the hard/soft situation is normal,thats just the power assist kicking in when the engine is started and booster gets vacuum...search other threads for adjustment,mines manual so i'm not positive...usually rod in booster is threaded...you just want a tiny bit of clearance between it and master..you shouldn't have to push on master to get it to touch booster(not easy to feel now that lines are on)
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Old 06-22-2013, 10:27 AM   #8
Ol Blue K20
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Re: Rear brake seizing..... help!

If releasing fluid helps, you may want to replace the rear flex hose. They get old and the inside collapses. The master has enough pressure t push through it but the return springs can't return it all and brakes drag
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Old 06-22-2013, 01:02 PM   #9
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Re: Rear brake seizing..... help!

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Originally Posted by six8burban View Post
Ill check, just loosen a little?
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If you can pull the drums off with little effort then the shoes are adjusted ok. Make shure all your springs and hardware are installed correctly. some guys like to have the shoes drag on their drums and some dont.
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Old 06-23-2013, 05:20 PM   #10
six8burban
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Re: Rear brake seizing..... help!

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Originally Posted by cdowns View Post
X2 on the pushrod clearance problem
.....I just unbolted master to see if I could see push rod.....I don't. Is this normal when vehicle is off?
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