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Old 03-28-2018, 05:15 PM   #1
Awann99
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Drum Brakes Sticking

The rear brakes in my 1969 gmc 1500 will engage but won’t disengage once I let off my pedal. The brakes became so tight while I was driving that it caused my transmission to overheat. I took the drum off and the shoes will push out but won’t go back it. The truck sat for a year while it’s engine was out. What could be causing the brakes to not disengage
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Old 03-28-2018, 05:41 PM   #2
rockyrivermark
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Re: Drum Brakes Sticking

Quote:
Originally Posted by Awann99 View Post
The rear brakes in my 1969 gmc 1500 will engage but won’t disengage once I let off my pedal. The brakes became so tight while I was driving that it caused my transmission to overheat. I took the drum off and the shoes will push out but won’t go back it. The truck sat for a year while it’s engine was out. What could be causing the brakes to not disengage
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Could be a number of things but I'd put on new wheel cylinders to start with.
They are inexpensive good chance the prob or at least part of the prob.
I would also install new spring kit while it's opened up, also inexpensive.
Do the drums spring freely once it sets a while?
Adjust drums and rubber hose also causes this symptom if it's old and narrow inside tube


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Old 03-28-2018, 07:16 PM   #3
Steeveedee
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Re: Drum Brakes Sticking

If both sides of the rear brakes don't return, it's probably the flex line to the differential. Depending on age, you may want to look into wheel cylinders as well, just to be sure you don't have a leak. All that takes is pulling the outside dust boot off the cylinders and look for fluid.
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Old 03-29-2018, 09:57 AM   #4
Myoldtruck
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Re: Drum Brakes Sticking

I had similar problem when i got my truck two years ago, mine was related to emergency brake cables. I oiled the heck out of the cables from the cab back. I also replaced all rubber parts, cyclinders, hoses. Wire brush all parts in the drum and use anti seize on backing plate where the bumps are and on upper pin. clean and anti seize the lower adjuster so it spins very easy in your fingers, the grove end is suppose to spin on it also. Position your shoes properly, there is a front and rear shoe.

Once there right they will work good. I still have to manually adjust the shoes once a year, the self adjustment works when it wants to ive found.
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Old 03-29-2018, 11:20 AM   #5
Mts67C10K20
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Re: Drum Brakes Sticking

Had a similar problem with my rt front
The hose had collapsed internally
Like stevedee said check / change the rubber lines
Good hunting
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Old 03-29-2018, 01:39 PM   #6
alsriv2
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Re: Drum Brakes Sticking

In past trucks I've owned, many of the pulling or brakes dragging issues I have encountered have been due to the rubber flex lines constricting the flow due to deterioration or damage. Heck my daughters '02 Furd just got new flex lines on her front disk brakes as one caliper would not apply (brake) correctly and would cause her to change lanes under firm braking and then that side would drag for a few miles until the fluid could return. The new lines have stopped all her braking issues.
On our trucks, when not knowing how old the brake lines are, it is best to replace the flex lines and prevent troublesome issues like you are having.
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Old 03-29-2018, 01:41 PM   #7
davepl
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Re: Drum Brakes Sticking

Yeah, if it's both sides, about the only thing in common they share is the fluid path, so you figure it's going to be the lines.
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