I have a '70 'stang and I'm having trouble getting pressure on the brake pedal. I have manual brakes. I noticed that brake fluid was leaking up out of the brake pressure switch on the proportioning valve. I put a new brake pressure switch in and the same problem occurred when I tried to bleed the brakes. Has anyone had this happen or know what to do? I don't want to be replacing parts that don't need to be replaced. Is it leaking do to the proportioning valve or is it a bad switch again. I'm getting no where. Please help if you can.

 

Two bad switches, could be, but I am thinking that the fluid is leaking somewhere else. Brake fluid seems to "wick" and wander, making it kind of difficult to find leaks.

The best advise I can give from here is to keep looking for the leak.

Might want to clean it up real good and apply some kind of powdery dust to help find the origin of the fluid. I don't know, maybe baby powder, flour, or baking soda...

 

It's leaking right up through the switch. Is there something wrong with the distrobution block that could be causing it?

 

You shouldnt have brake fluid to the switch. There are two seals on either side of the shuttle that should keep the fluid from reaching the switch. You need to take the distribution block out. Unscrew the switch from it, take the end cap off and pull the shuttle out. Clean the inside and the shuttle up as best you can and replace the two seals.

I would say you are fighting a air bubble that is floating around in the distibution block and fluid leaking past the seals.

 

master cylinder might be no good