One rear brake locking up... after brake job?

1964 Buick Wildcat, drum front, drum rear.

Since getting back my Gaines built motor and Telesco rebuilt carb and distributor, I have been absolutely tearing up the roads. I noticed my passenger rear drum locking up far before the others, and had a real soft pedal. When I took the passenger side apart, I found a cracked brake shoe, and then a stuck rusty wheel cylinder, which likely led to the cracked shoes.

I threw the parts cannon at both rear wheels. New AC Delco wheel cylinders, new brake hardware, new brake shoes. Bled all 4 corners. Have excellent pedal feel. E-Brake works no issue. Issue is now, the driver's side wheel is locking up far before the others. Passenger side is A okay, which is where the cracked shoes and stuck cylinder were originally. I've pulled the driver drum back off, and completely backed off the adjuster, but that wheel is still locking up prematurely.

I'd appreciate all your thoughts and suggestions. Picture is right before I put the drum on, video is it locking up.

 

It might be the way the picture makes it look, but the wheel cylinder 'push rods' seem to be out quite a bit for new shoes?!
Just a thought, the smart guys will be along shortly!!

 

could the wheel cylinder be upside down? or do they only fit one way?

 

Is your bottom spring in?

 

Hello Adam, I'm not doing a full panic stop on the brakes, but I'm also not just coming to a casual stop. I'd call it a moderate stop. I didn't have the drums turned, as they were turned 2,400 miles ago. Now, that was a decade an a half, but nonetheless, only 2k miles.

 

What's the diameter of the drums??? You need to go to a brake shop that has a drum mic. Now-a-days will be kinda hard to find a shop that has one. You may get lucky at an older shop. Are the brake shoes bonded or riveted???

 

Not sure of the diameter right this second, but I do know when I lifetime warranted the shoes, they went from being riveted, to these new ones, which are strictly bonded.

 

It is indeed install. Question, do you know if it has a "polarity"? I have two before pictures at two different times, with the bottom spring two different directions.

 

Wouldn't air in the line cause it to lock up? or just the opposite?

 

Try switching the drums side to side and see what happens.

 

When I first saw this this morning, my first thought was the adjuster. There are many adjusters, it appears the one in your new pic is longer than the one in your old pic. But, before you even posted the second pics, the adjuster looked too long to me. I was thinking this AM, that was the reason the brakes were grabbing, like the shoes aren't going in and out evenly. What Adam said, the spring has to be right there, too. You should crimp that yellow spring a bit more, too.

 

Sometimes with age the inside of the flexible brake lines will collapse causing the breaks to lock up. On my car it was the flex hose that goes to the T where it splits the line to both sides of the rear axel. When it collapses it acts like a check valve preventing the wheel cylinder to release the pressure.

 

It sounds crazy but sometimes if the shoes are too far away from the drum they will grab like that. Worth looking at???

 

Did you check the radius of the shoes to make sure it matches the drums?


Keith

 

Need to flip the spring end to end on your left picture..



.

 

Was able to take the brakes apart tonight. A few status updates for the group:

-First, I can confirm I have the spring for the adjuster installed correctly per Redmanf1s picture above. Thank you guys for the prompt reply.
-Two, self adjusters are working. During previous troubleshooting, I re-installed them all the way together, and you can see, they have adjusted out a few turns.

Extreme brake lockup:
Second, I backed the parking brake nut off two turns under the car and now don't have extreme pre-mature lockup of the driver's side. I can't tell if the lock up is completely gone, but I'm not making a tire smoke trail on camera anymore.

New wrinkle:
I was hearing a grinding noise out of my passenger side. Turns out my lifetime warranted brake pads are just a hair too wide on one side and are cutting into the front of the drum. Researching solutions now that don't involve the parts cannon, so open to any suggestions.

 

Belt sander or mini grinder with a flappy wheel to remove a small amount of material from the brake shoe edge.

 

X2 on what Matt said, I was thinking the same as I was reading your post.


Keith