Sign in to follow this  
ceejay

Brakes on your 42 to 48 Buick-Describe them

Recommended Posts

Hi all,

I am having "trouble" with the brakes on my 46 4 door super.

New master cylinder, all new seals in all wheel cylinders.

The pedal requires a LOT of effort and does very little to stop the car.

Even with a lot of effort on the pedal, the wheels can not be locked... the car does slow down but it is no where near enough braking.

Just wondered what the brakes are supposed to be like on these cars.

Share this post


Link to post
Share on other sites

On my 48 Special Sedanet I replaced all the wheel cylinders, new hoses and rebuilt the master cylinder. Pedal is hard and effective. I have never had to lock the wheels so I cannot tell you I could but these brakes are very good.

Joe, BCA 33493

Share this post


Link to post
Share on other sites

At first, after installing the new master cylinder and rebuilding the wheel cylinders, I was running the car with the brake linings that were on it.

They were not worn off and had bedded in well so I figured I may as well use them

Then after having this in effective brake issue from the start, it was decided that maybe the linings were old. When inspected after some use, the linings and the drums were "polished" so it was decided to get the shoes re lined.

The new liners have bedded in now but still the brakes are the same.

The brake pedal is hard... not spongy but even with a lot of effort, it doesn't slow the car down much.

Can you guys tell me.. what diameter seals should the wheel cylinders and the master cylinder use ?

Share this post


Link to post
Share on other sites

When you were bleeding the brakes, did fluid flow with a forceful steam?

I sounds like some of the wheels aren't getting fluid.

On gravel or dirt can you LOCK up the wheels, have someone watch and see if ALL wheels are locking up.

I don't recall reading that you replaced the brake lines?

Dale in Indy

Share this post


Link to post
Share on other sites

Did you change out all three brake hoses? They may be restricted. I've seen old brake hoses swell up to the point that a pencil lead would not fit inside. I'll find a picture of one I removed from my '47 Roadmaster when I find it. These cars have very good brakes.

Share this post


Link to post
Share on other sites

HI all,

Thanks for your input.

I did not install new hoses but they seem to be free of blockage.

Usually when hoses get blocked, it is difficult to bleed the brakes as the flow of fluid is poor and also with use, the brake bind as the fluid does not return to the master cylinder.

I have neither of these symptoms.

However, the wheel cylinder and master cylinder sizes are suspect.

The previous owner had sleeved the wheel cylinders and I just installed new seals to the same size as what was in there. I'm not sure if they have sleeved it to an incorrect size.

The master cylinder on the car was a 3/4" internal diameter british lockheed master cylinder and I replaced it with a new one of the same type.

Here again, im not sure if the 3/4" size is correct for the car.

Also the brake lining material i'm using may be too hard..

I'm guessing that all of these combined, could be causing the bad brakes.

Would greatly appreciate it if someone can tell me correct internal sizes for the wheel cylinders and master cylinder

Share this post


Link to post
Share on other sites

The last time I bought a MC repair kit for my 55, the application said 1940-1955. My 55 has a one inch bore. Take that for what it's worth.

On the shoes, I bought new shoes for my car recently and I discovered that there was a slight ridge on the outside of the new shoe. I sanded it down, and the brakes stopped much better. It has also been said around here that the new linings are too hard. That may be an issue as well. Remove your drums (first) and check to make sure the shoe is wearing evenly. If there are some "slick" spots and unused spots, you should take the drums and shoes to someone who can match the arch of the drum.

Good luck, nobody likes driving on brakes you can't trust. Actually, we don't like you driving on brakes you don't trust. ;)

Share this post


Link to post
Share on other sites

Replace the hoses, just to remove that variable.

Be sure the shoe with the short lining is facing towards the front of the car on all 4 wheels.

That 3/4 inch bore master cylinder will actually develope higher braking pressure than a one inch bore.

Raybestos brand linings gave me the same trouble on a 55 Century with power brakes.

Custom linings can be installed that have better friction properties.

Willie

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this