I have been tasked with trying to complete a conversion / resto-mod that a friend's son started and am hoping I can find some help here.

I am working on a 65 fastback that originally had manual brakes. The owner converted the front suspension to 5 lug as well as the rear axle for looks and to support the weight / power of the V8-302 I installed for her. They switched from manual brakes to power boost, and I can not get them to work properly. The brakes are all adjusted but the pedal goes most of the way to the floor. I have a vacula brake bleeder and have sucked A LOT of fluid through the system, no air seen, bus still a pedal that is almost on the floor.

Drum front and rear. I installed a master cylinder, proportioning valve and other items provided by the owner, all new. I am at a loss... HELP!

 

Sorry to sing the same old song, but if you have no pedal at all you have...

a. air in the system

b. defective master cylinder

c. leaking fluid

d. The m/c push rod is not coming all the way "home" when the pedal is released.

I vote for air in the system, try a good long gravity bleed.

 

Air in the system... possible

defective master... possible

leaks... none

m/c pushrod issues... does not appear to have any.

I will give it a good, long gravity bleed and see where it goes from there. Very frustrating picking up where someone else left off, and screwed things up...

 

Did you bench bleed master cylinder before installing it?

 

May not be relevant, but a drum/drum system has no use for a proportioning valve.