Amazon: Brake trouble - one or both rear brakes lock up

[DOGSTAR]

Have you checked to see when you have the vehicle up on stands the rear wheels spin freely? if not it may well be the brake shoe adjuster is incorrectly set, the adjuster is located on the back plate of the drum at the bottom, adjust it first by tighening so the wheel is fixed, then undo until the wheel spins free. you need to do this both sides. The variants of the amazon have different brake set up so front disc single circuit no servo, front disk single with servo etc. Volvo used a 1 inch bore dependant on vehicle type and chassis number but was found if your vehicle was fitted with a servo and brake cylinder with a one inch bore it tended to lock the brakes at the rear, so generally the brake cylinder was swapped out for the smaller bore size thus reducing pressure applied through the system.

Originally Posted by samaron

Hello everyone,

Hopefully someone here has some experience that can point me in the right direction on where to troubleshoot.

Ever since I bought my Amazon, I have had a strange problem where one or both rear brakes lock up when braking. I believe it is the rear left that lock up, but hard to tell. My car isn't fitted with a brake servo, just a regular single circuit brake system.

Normally this occur after the car has been sitting overnight. Just a light push on the pedal and a very brutal stop ensue. Luckily this tend to happen at walking speeds, but I have experienced this at higher speeds too. Braking afterwards performs as normal.

A year ago I had the car at a shop as I don't have an appropriate brake puller. None I bought fit the bolt pattern, and a claw type puller took out a piece of the drum rather than pull it off. The shop replaced the brake shoe linings, springs, performed some cleaning and lubrication. They did say one of the brake cylinders were leaking, and the provided overhaul sets did not fit, but they managed to fix it regardless.

Some other things to mention are that all brake lines and hoses have been replaced the past year. The handbrake is, as far as I understand, properly adjusted. 4-5 notches before it is fully engaged. Brake fluid is replaced and stays at the same level without discoloration.

Since I'm driving the car a lot more now, I probably should get this looked at again. Have taken some measurements and will attempt at getting a brake puller made. Meanwhile I could order up some brake parts. Is there anything I should order up and have ready? When I do get a brake puller made, are there any prime suspects among the brake parts that I should focus on?

[samaron]

I appreciate the reply, but I have a completely different brake system. Apparently the most uncommon one, in fact. I do not have manual adjusters like the ones found on 60s cars. I have drum brakes with automatic adjusters. Only used on model year 1957 and 1958.

Replacing the rear wheel brake cylinders solved the issue with the brakes locking up. They were full of rust. The only reason the brake performance is okay-ish at the moment is because I have new brake shoe linings and minimal wear.

In my case, one of the consumable parts needed for the adjuster mechanism to function is discontinued. The hand brake cable is discontinued also. Have spoken with a parts dealer and am in the process of working out what I need in order to do a brake system swap to a mid-60s setup. It is looking positive, and should hopefully have much better availability with parts for many years to come.