Brakes on 39 ford

[dshortw@aol.com]

I have replaced all wheel cylinders & master cylinder . The brake shoes were good. The car was stored for over 20 years. After Bleeding the Brakes & getting the air out of system .The brake pedal locks all wheels but goes to floor & will not build pressure.

 

[V8COOPMAN]

I have replaced all wheel cylinders & master cylinder . The brake shoes were good. The car was stored for over 20 years. After Bleeding the Brakes & getting the air out of system .The brake pedal locks all wheels but goes to floor & will not build pressure.

It could be a couple of things. The shoes really need to be adjusted ACCURATELY to start-out as near the drum as possible. If not adjusted as such, much pedal TRAVEL distance can be used-up before the shoes contact the drum, which sounds POSSIBLE in your case. Click the link below for the old-time instructions to adjust the EARLY hydraulic backing plates (1939-'41). You must remember that there are adjusters at the BOTTOM of those shoes, as well as another set of adjusters about half way up the shoes. Make sure you do the adjustments in the proper sequence. It CAN take some practice and PATIENCE to get the hang of adjusting these PROPERLY, but it will pay-off handsomely.

https://www.fordbarn.com/attachments/12967/

One more possibility is the "free play" adjustment at the rod from the brake pedal to the master cylinder. There should be ONLY about 1/16" of free play (brake pedal movement BEFORE moving master cyl piston). MAKE SURE THOUGH, THAT YOU DO HAVE this approximate 1/16" of free play ! ! Any more than that will amplify the symptoms you speak of. Good luck! DD

 

[W1964]

The reference by V8COOPMAN in the post above : https://www.fordbarn.com/forum/showthread.php?t=210364&highlight=brake+adjustment

From what book is this taken from?
Thanks for your response.
Bill

 

[Tinker]

Then there is brake shoe arching, a lost art. Not what your experiencing with pressure.

 

[Kurt in NJ]

I have found that all wheel cylinders of modern offshore production need to be taken apart to inspect that the bleeder screw passages are drilled correctly, some are not drilled to intersect the top of the bore-- and some even the fluid passage is drilled so that the passage is covered by the cup causing leaks--- if the bleeder passage is not at the top of the bore air will be trapped

Also resleeved cylinders should be taken apart to see if all the shavings and honing grit was cleaned out-- I have had newly resleeved rebuilt cylinders leak because of shavings embedded in the cups