Power Brakes 56 Buick

[Guest]

I have a 56 buick special with power brake. I'am now on my third brake booster

in four years. The boosters have all failed, they start leaking from the vaccum

releif hole in the front and after a while the brake fluid is sucked up through the vacuum hose and burned in the engine and I have no brakes. I have had one booster rebuild twice and now I have a new rebuild with a new casing. Pulled it out last week and there's that spot of brake fluid, so this one is starting to fail also. I,ve blown out the brake line and us DOT 3 brake fluid. What's happening? Any help will be appreciated.

[Judd]

Jeff

Are you rebuilding the master cylinder with the booster? If not maybe the master cylinder is leaking into booster and destroying the seals????

[Guest 53and61]

I've had good luck with Booster Dewey in Portland, 503 238-8882. (I think the phone number is right but can't guarantee it.) He was willing to trouble-shoot over the phone and provided a good rebuilt booster/master. Dewey knows brakes.

[Guest]

Tried that number for Dewey but it doesn't go through. Is this a company that might be listed somewhere? Let me know and thanks

[JohnD1956]

Several years ago I had my master cylinder rebuilt by a place in California. It was in Ontario California, but I can't recall the name of the place. Anyhow, they were very good, and the product works great today, which is at least six years after the job was done. I did send them the entire brake unit, booster and cylinder. It took several weeks but that was partially due to shipping etc from NY

John D

bca#3757

jld1972@empireone.net

[Guest 53and61]

Sorry about the dud phone #. I dealt with him about 6 months ago and had found him in Hemmings. I don't have a current Hemmings, but I did find the following address on the internet. Power Brake Booster Exchange, Inc., 4533 SE Division St., Portland, OR 97215.

[56Roadmaster]

Hi Jeff,

I am guessing you observe all the cleanliness rules of rebuilding, i.e. not using petroleum based cleaners. Is there any minute pitting on the piston shaft? also do you follow the factory proceedure for setting the pedal position when connecting to the push rod- improper alignment could be causing heavy wear on one side of the seals, also that bronze bushing inside the fluid side might be worn-if If I remember that doesn't always come in the seal kit- you should check that with dial calipers and compare it to specifications.

It sounds like you have a centering issue caused by worn tolerances or improper alignments which allows distortion of the seals..it doesn't take much.

Also check for burrs on the fluid piston shaft (very very small) which might cut the seal over time.

Also check the outer diameter sealing surfaces of the cups, any corrosion in the cylinder bore or the end cap (part with spanner holes) will provide a path for the fluid to leak around.

Finally are you getting a good quality seal kit?

If you don't have the shop manual I will be glad to send you a photo copy of the procedure, I aslo have the 56 parts book which has a nice exploded view of the 56 power cylinder which I can copy.