At My Wits End With 52 Special Brakes Need Sum Help!!!

[shadetree77]

Ok, I have a 52 special that I just bought. The car basically had no brakes. If you pushed the pedal all the way to the floor it would slowly roll to a stop. So I have rebuilt the entire brake system. Put a rebuild kit in master cylinder, 4 new wheel cylinders, new rubber hoses, new shoes, and new springs. I have taken all of the junction/distributor blocks off and cleaned them as well. I have bled the brakes what seems like 100 times. I have adjusted the shoes out til they rub lightly on the drums. I have adjusted the pedal linkage. I also cleaned the master cylinder cap as I read somwhere that the vent holes being clogged could lead to bad brakes. There are no fluid leaks that I can see. All this and I am STILL at square one. The brakes are the same as they were before I started all of this! The pedal is soft and goes all the way to the floor before the brakes lightly kick in. I just don't get it! I really don't want to send her to a mechanic but I just don't know what else could be wrong. I just read in the buick service manual that there is a gasket that goes on the screw-in cap for the master cylinder. Mine does not have a gasket. Is this little gasket that important? Does anyone else have a similar master cylinder that does have this gasket? Any help or suggestions would be appreciated. I just want to drive(and stop) my Buick!!

 

[suntreemcanic]

I know what you mean, I hate to give in and hire someone to fix something that I can do. I hate to admit defeat. Are you getting fluid flow when you step on the brakes? You could check that by loosening a bleeder on one of the wheel cylinders and have a helper depress the brake pedal. A substantial amount should come out. There is two types of bleeding philosophies: pressure bleeding and vacuum bleeding. You might consider the other method you are not currently using. You could also eliminate the rear brakes by putting a plug in the system and then deal with only the front brakes.

 

[njlimbaugh]

I once rebuilt brakes on a 37 Dodge that did exactly as you describe. Turns out that the drums had been turned and the new shoes I installed were standard size. What happens it; the shoes only contact the drums with a small patch in the center which makes two things happen: the shoes flex somewhat but still don't make full contact with the drums, and the amount of shoe surface contacting the drums generate so much heat that they fade almost immediately. Check the inside diameter of the drums and compare with the diameter of the shoes. I made a gauge equal to half the diameter of the drums that would swing around the hub then, with the drum off, I adjusted the shoes out to where they contacted the gauge. If the shoes are too small, they won't make full contact on the gauge. Next step; either get new, unturned drums or find oversize shoes and get them turned to the proper diameter.

 

[telriv]

Even though you rebuilt the master cylinder it could be "Sucking" air when you let the pedal up after bleeding. One way to test this theory is to pressure bleed the system. If the brakes are OK for the 1st. few applications then for sure the master is sucking air. The only remedy then is to find a NEW M/Cyl. or send yours out to be bored & sleeved to it's original size. Been there, done that.

Tom T.