To recap, I'm going from 4 wheel manual drums to power front disks on my 68, with all mustang parts. I obtained disk brake spindles and distribution block from a donor mustang, and bought everything else new. New booster, Master cylinder, Adjustable Proportioning valve, Power Brake pedal, calipers, lines, etc.
We bench bled the MC, and bled the system thoroughly.
Here's what I am experiencing:
1. The car will stop fine, but the pedal feels very soft with a lot of travel. I've never driven an old Stang with power brakes, so I have nothing to compare, but it doesn't feel right.
The pedal seems to have great pressure and feel, until I start the car. Then it goes soft.
2. Bigger problem: The pedal will not return on its own, and the brakes stay engaged until I pull the pedal up with my foot. WTF?
As I said, we bled the system well, over and over again. There are no leaks. I have a vacuum line running from the booster to the intake. I put the adjustable prop. valve where the stock one would have gone, in line between the 2 rear ports on the distribution block (the power dist block has 2 extra recepticles in the back). No amount of adjustment on it changes the problem. I checked my restoration guide, and made sure the valve is orientated the right way according to IN and OUT (bottom of the dist. block to IN, and OUT to the top of the dist block).
I used DOT 3 brake fluid.
Did we miss something? Do you have to lengthen the MC pushrod, even if you are using all the original spec parts, including the brake pedal? I left the back drums alone (still stock). Does anything need to change back there?
We are lost as to what to do to fix this.
We bench bled the MC, and bled the system thoroughly.
Here's what I am experiencing:
1. The car will stop fine, but the pedal feels very soft with a lot of travel. I've never driven an old Stang with power brakes, so I have nothing to compare, but it doesn't feel right.
The pedal seems to have great pressure and feel, until I start the car. Then it goes soft.
2. Bigger problem: The pedal will not return on its own, and the brakes stay engaged until I pull the pedal up with my foot. WTF?
As I said, we bled the system well, over and over again. There are no leaks. I have a vacuum line running from the booster to the intake. I put the adjustable prop. valve where the stock one would have gone, in line between the 2 rear ports on the distribution block (the power dist block has 2 extra recepticles in the back). No amount of adjustment on it changes the problem. I checked my restoration guide, and made sure the valve is orientated the right way according to IN and OUT (bottom of the dist. block to IN, and OUT to the top of the dist block).
I used DOT 3 brake fluid.
Did we miss something? Do you have to lengthen the MC pushrod, even if you are using all the original spec parts, including the brake pedal? I left the back drums alone (still stock). Does anything need to change back there?
We are lost as to what to do to fix this.