1939 brakes

[fleetpaint]

The Brakes on my sedan are very spongy! I have replaced shoes, hardware, changed fluid, & bleed them 3 times. No air in the lines. Could the master cylinder be bad without leaking?

 

[Ken/Alabama]

Did you adjust the lower anchor pins to center the shoe in the drum. There are some very good instuctions on how to do this on the Techno Source website.Flathead Tech source

 

[fleetpaint]

I have centered & adjusted brakes. It cant be this difficult?
i adjusted the brakes so the wheels wont turn, still low & super soft pedal?

 

[Scott De Shields]

Rubber brake hoses good?

 

[fleetpaint]

the hoses arent leaking?
how do i know if they are good?

 

[alanwoodieman]

to check for weak hoses have someone apply the brakes while you are holding the hose (S). If they are bad they will "grow" in your hand. Adjust the master cylinder till you have about 3/4" play in the pedal before it moves the piston

 

[fleetpaint]

to check for weak hoses have someone apply the brakes while you are holding the hose (S). If they are bad they will "grow" in your hand. Adjust the master cylinder till you have about 3/4" play in the pedal before it moves the piston

good advise!...will try that next!....thanks!

 

[Clem Clement]

DOT 5 will give you sponger brakes than DOT 3. Clem

 

[Fred A]

Drum brakes that are not well centered can take some time to firm up. I put Lincoln rears on my '47 front and somehow didn't do the best job on centering. Into it over a thousand miles and they are now well seated and working more as expected. Still just a hint of pulling to the side thats getting better.

 

[George/Maine]

When putting new brakes should brake the ends with a chamfer and make sure the middle of shoes hits drum.

See the chamfers on ends.

http://www.jalopyjournal.com/forum/picture.php?albumid=23029&pictureid=307739

 

[jerry grayson]

I have centered & adjusted brakes. It cant be this difficult?
i adjusted the brakes so the wheels wont turn, still low & super soft pedal?

Some times it is difficult!! Did you arc grind the shoes? If so, and all the air is out you have an adjustment problem.

 

[rotorwrench]

Cars with low mounted master cylinders are sometimes difficult to get all the air out. I wrap the bleeder nipples with teflon tape to insure no leakage at the threads during the bleeding process then I pull the fluid through with a vacuum pump into a jar of fluid with clear Tygon tube so I can see the bubbles until they disappear. The old pressure bleeder pots were the best. They just push the air back through the system into the master cylinder reservoir. Either way you have to keep an eye on the fluid level in the master reservoir so it doesn't run out or run over depending on the process used. I always start with the wheel cylinder farthest away from the master & work it closer step by step.

Gone are the days when every little town had a shop that could grind the shoes to the drums like there used to be.

Kerby

 

[fleetpaint]

Thanks for all the help guys!
The problem was the master cylinder. Replace it, now have good brakes! ( I think I am now an expert on 1939 brakes!..lol)