oldsguybry

I must be a magnet for oddball problems lately when it comes to older cars . The wife's 01 Crapalier Z24 has an issue with the back brakes locking up right as you come to a full stop . It WAS the passenger side , but now it seems to switched to the driver side . The brakes are adjusted right , and I replaced all the hardware and springs . I also replaced the brake shoes last fall , along with the drums . It didn't do this right away , so the only thing left is the wheel cylinders , limiter valve , or the ABS ?

svnt442

It sounds to me like the brake shoes are shifting and causing the lockup. I would inspect the backing plates and all of the mounting locations for excessive wear and signs of the shoes shifting too much.

RetroRanger

I had a rear wheel lock up situation on a truck after ~1 yr old brake job, one pad had partially delaminated and broke off leaving it to float around and occasionally jam up the operation.

oldcutlass

Make sure the wheel cylinders are moving freely and not leaking. If the shoes had been saturated in brake fluid or gear oil in the past, replace them.

oldsguybry

One wheel cylinder is getting bad but not leaking .... yet . Both sides seem to have the issue like the adjustment is too tight , but the drum slides right off ( too loose if anything ) . I backed the brakes off to see if this would help , but it goes right back to the same thing again after a few days . This is why the biggest suspect seems to be the valve or valves that regulate the fluid to the rear brakes . I've been fooled before though .

droldsmorland

Primary and secondary shoes on in the correct direction??? Primary(shorter) shoe faces forward. Also, consider replacing the rubber line to the rear system. Especially if its original.

oldsguybry

I will check on this , thanks for all the replies .

oldsguybry

Well , the shorter shoe is facing forward but seems to be worn more then the longer side . The new pins that go through the backing plate seem to have a lot of play in them , are they suppose to have a bushing supporting the pin in the backing plate and the shoe itself ? There's only one on the other side supporting the metal plate going to the adjustment wheel .


I ask that question because I can move the steel plate out pretty easily that's supposed to stop the adjustment wheel from moving freely , in other words , I can move the adjustment wheel in either direction by hand when the metal tab is up against the wheel .


Lastly , are the top springs hooked up correctly shown below ?


I can understand the backing plate being worn out , but on both sides at the same time ? I'm beginning to think the auto parts store sold me the wrong crap or something .

DJS70cutlass

All the J bodys do this after a while. The root of the problem is aftermarket shoes are a bit too wide. Just chamfer the edges of them a bit, more on the outside than the inside, and it'll fix your issue! Everything in your pics looks ok!

oldsguybry

I tried sanding the shoes down a bit , but the shoes facing the front of the car were worn down considerably . The drums were pretty warped too , so I bought new shoes and drums . The car drives like new again , but I can tell after a couple of weeks that the same thing is going to happen . I need backing plates bad , along with new wheel cylinders . I hope this will do the trick because I don't want to buy new drums and brake shoes twice a year .

The problem is .... I can't find backing plates anywhere .

oldcutlass

Those shoes are not worn much from the pics. All the pins do is hold the shoes against the backing plate. The upper pin in conjunction with the springs guide the shoes back into place. The shoes when extended self center on the drum. Make sure there is minimal distance between the shoes and the drum after they are adjusted. If the self adjuster arm is not in the proper place on the adjustment wheel its because the cup and pin spring is not seating the arm flat against the shoes.

cjsdad

Unless you have severe grooves worn into the backing plates they probably don't need to be replaced. There should be tabs on the brake shoes where they ride against it and a small dab of anti-seize will help them move more freely. The brakes will self-adjust when you step on the brakes as you move in reverse.

oldsguybry

Thanks , maybe the plates aren't the problem then .

oldsguybry

Do you think that the cheap metal clip doesn't hold the brake shoe against the backing plate tight enough ? It seems I can move the shoes by hand a little to easily . I believe I have the adjustment wheel set up in the right spot also .

oldsguybry

So I need them to move more freely ? I thought they moved to easily as it was . Man , this is another one of those weird problems I have to figure out , I'm running out of parts to replace lol

cjsdad

The brake shoes should move freely enough to return to neutral position when you release the brake pedal. When adjusted properly they are only moving 1/16 inch or less. If the shoes bind and don't return to neutral position they will rub against the brake drum and overheat and warp. The small clip that holds the shoes to the backing plate is really only there to hold everything in place 'til the drum is installed. The top springs should be quite strong so as to pull the brake shoes away from the drum and back to neutral too. The only thing I would question is the adjuster, it should be riding fairly tight against the adjustment star wheel so it cannot turn by itself. It should only turn if the shoes get loose enough that the adjuster catches the star wheel and turns it. That shouldn't happen very often.