rear brakes sticking

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Longgone

Longgone

John/68 Barracuda & Dart
Joined
Jul 12, 2005
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Newport News, Virginia
I recently changed the rear wheel cylinders on my car. They are 10" drum brakes. The brakes were working fine but one cylinder was leaking so I changed them both. ( I was taught that was the thing to do). Now the brakes are sticking. I`ve checked the parking brake and everything looks good there. I`ve adjusted the brakes up and down and tried letting them auto-adjust with no change. I`m wondering if I`ve got the wrong wheel cylinders or something? I`ve seen where there`s cylinder stops on either side of the wheel cylinders and I`m wondering if the cylinder pistons can be getting caught up around them. I don`t know what to look for. Any suggestions?
 
I would say you have the wrong cylinders. Everything has stayed the same except the cylinders. But you should be able to compare the old with the new. Do they measure the same width? Are you sure the springs and things are all in there proper place?
 
Just wondering if the rear brake hose collapsed, not allowing the rear brakes to release after being applied ?

Will the car roll in neutral forward and back?
 
Johnny, did the shoes get any fluid on them. Even a little will cause them to do that. Tom
 
mullinax95 said:
I would say you have the wrong cylinders. Everything has stayed the same except the cylinders. But you should be able to compare the old with the new. Do they measure the same width? Are you sure the springs and things are all in there proper place?
Click to expand...

They appeared in everyway to be the same with the exception of the bleeder screw being longer and smaller (in diameter) on the new cylinder. The part I didn`t measure was the piston diameter and I`m wondering if it`s the right one. I`m certain the springs are all installed correctly.

6pk2goDemon said:
Just wondering if the rear brake hose collapsed, not allowing the rear brakes to release after being applied ?



Will the car roll in neutral forward and back?
Click to expand...

The car won`t roll without persuasion (in the form of a fair amount of hp) It seems that many rolls back and forth will break things loose enough to get going. I`ll look at that hose, thanks 6pk.

fishman said:
Johnny, did the shoes get any fluid on them. Even a little will cause them to do that. Tom
Click to expand...

Hey Tommy, one side got wet but not soaked. Went through a can of brake clean per side and cleaned up the shoes with sandpaper. Even got AO to turn the new drums (and they were out). Parking brake works without a hitch and I replaced the return spring on the strut. It started when I replaced the wheel cylinders so that`s why I`m leaning toward that. It seems more hydraulic than mechanical. I guess I could try to crack a bleeder and see if the shoes retract. That should tell me if it is hydraulic. If the piston is smaller than factory spec is there any way the it could get hung up on the stops? I`m at wits end, I just don`t know where to go next.????
 
Find a friend to help you do this.
Taking one side at a time, remove the drum and gently push in the pedal till the shoes move out a bit, relax the pedal and see if it retracts, put the drum back on then go try the other side.
If only one retracts you know the other one is the culprit.
If neither retract then it might be the hose, or...unlikely but possible...both the cylinders are bad.
Good luck, and keep us posted.
 
charger70 said:
Find a friend to help you do this.
Taking one side at a time, remove the drum and gently push in the pedal till the shoes move out a bit, relax the pedal and see if it retracts, put the drum back on then go try the other side.
If only one retracts you know the other one is the culprit.
If neither retract then it might be the hose, or...unlikely but possible...both the cylinders are bad.
Good luck, and keep us posted.
Click to expand...


That's a good idea.
 
peek under the boots and see if the pistons were installed baclward. I know this sounds crazy but I've seen it before.
 
I hate to say it but look at the brake shoes,make sure the shoe with the least amount of friction material(primary) is towards the front of the car and the one with the most(secondary)is toward the rear,make sure they are not the same.that will cause the brakes to lock up.I have seen people put two primarys on one side and two secondaries on the other,either one of those will cause lock up.let us know what you find and good luck.
 
I went ahead and bought another set of shoes. I checked the brake hose and it appeared to be turgid throughout brake pedal movement so I moved along. After removing everything, I checked the wheel cylinders for the correct diameter pistons (15/16ths) and to see if the pistons were in correctly (per redfish) and all checked out okay. Just since I had things apart I removed the parking brake cables and lubed them. Waggin, I checked the shoes and they were on correctly so nothing was crossed up there but that would be easy to overlook if you`re rushing through things. I noticed on the backing plates deep grooves at the shoe contact area, perhaps enough to hang up a shoe? IDK? I sanded them but found out pretty fast that I would have to move to a grinder to get a flat surface again. After grinding them flat I sanded them smooth and lubed the contact area before reinstalling the new shoes. After everything was back together I adjusted the brakes out and took a little ride. NO STICKING! YESSSS! I can`t say if it was the deep grooves in the backing plates or the new shoes or a combo of both but it`s BACK! One odd thing is I never opened the system yet I had to bleed the brakes to get a good pedal again.??? Oh well, here`s a couple pics. You can see the grooves in the contact areas, then ground smooth, and finally each side back together.

IM000375 (Small).JPG


IM000380 (Small).JPG


IM000384 (Small).JPG


IM000385 (Small).JPG
 
Now you've done it... :-k Made me go to the dictionary...."turgid" :dontknow:

Glad you figured it out :cheers:
 
It`s not a word I use very much, hope I used it in the right context. It should mean like totally filled with fluid. ? Alright now I`m going to go look it up.:read2:
 
I looked it up and I got more definitions like "swollen" but I think it`s okay to use there. Anyway, I appreciate all of the input and I`m just glad things are back together and running smooth again. :burnout:
 
I like the way you did that,I use never sieze on those lil' pads.it works great for suspension bushings too.Nice job thank's for sharing the pic's and the experience.brakes are important,a car that won't stop right is only so fun
 
Ya know what ? I considered that but thought surely not. Never seen it but once in all the brake jobs I've done.
The car was a 68 Cutlass and those backing plates had to be replaced. Worn completely through
Those pads are one very few spots inside the drum where a tiny bit of grease is allowed.
 
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