[Tony G.]

converted to disk brake all 4 wheels , every thing works it just doesn't have gripping power I was looking for.
Brakes will not lock up wheels , it will come to a slow stop though. I have 11 in. drilled and slotted rotors 2 1/4 single caliper pistons in front 2 in. in rear with e-brake calipers . power brakes 8 in booster 1 1/8 master cylinder brake line 3/16 proportional vale for all wheel disk . I have bled brakes several times i can't see any more bubbles . Bleeding brakes from farthest to closest wheel .Car has been to 2 mechanic shops and they can't figure out. Brake kit is from Right/Stuff brakes
ANY BRAKE GUYS OUT THERE I NEED HELP , ANY ADVISE SUGGESTIONS?

THANKS

 

[tekctrl]

I changed our drum brakes to power (8" booster) discs in front and drums in the rear and they stop the car Right Now when I hit the pedal. Have you checked for vacuum leaks to the booster? Did you move the MC clevis down on the brake pedal to get some extra stroke?

 

[Stonecoldtx]

Try replacing master cylinder with one that has a 1" bore . . .

 

[Tony G.]

converted to disk brake all 4 wheels , every thing works it just doesn't have gripping power I was looking for.
Brakes will not lock up wheels , it will come to a slow stop though. I have 11 in. drilled and slotted rotors 2 1/4 single caliper pistons in front 2 in. in rear with e-brake calipers . power brakes 8 in booster 1 1/8 master cylinder brake line 3/16 proportional vale for all wheel disk . I have bled brakes several times i can't see any more bubbles . Bleeding brakes from farthest to closest wheel .Car has been to 2 mechanic shops and they can't figure out. Brake kit is from Right/Stuff brakes
ANY BRAKE GUYS OUT THERE I NEED HELP , ANY ADVISE SUGGESTIONS?

THANKS

Thanks for answering I will check for leaks and look into Clevis adjustment

 

[Tony G.]

Thanks for answering I will check for vacuum leaks and look into clevis adjustment

 

[Tony G.]

Try replacing master cylinder with one that has a 1" bore . . .

Local mechanic changed out m.c. It was a 1 inch piston diameter and there was no change in performance maybe I need a .8 inch m.c.

 

[Ace57]

Did both mechanics try pressure-bleeding system again ?

 

[Tony G.]

Did both mechanics try pressure-bleeding system again ?

Yes both mechanics claim to have bled lines I also bled lines my self

 

[Ace57]

Local mechanic changed out m.c. It was a 1 inch piston diameter and there was no change in performance maybe I need a .8 inch m.c.

No. The 1.25” is correct for power assist.

 

[SLIM]

No. The 1.25” is correct for power assist.

should say 1.125", which is my choice as well

 

[Ace57]

Thanks for answering I will check for vacuum leaks and look into clevis adjustment

Again, look into drilling a new clevis hole 1” below original hole (if your car originally had manual brakes) on brake pedal and relocate push rod there…which will lower the pedal ratio and engage brakes sooner in your pedal stroke. If you do this, make sure push rod doesn’t bind in master cylinder bore. You might need to shim bottom bolts of booster bracket to tilt booster/MC up a bit if they are flat mount brackets.

 

[Tony G.]

Again, look into drilling a new clevis hole 1” below original hole (if your car originally had manual brakes) on brake pedal and relocate push rod there…which will lower the pedal ratio and engage brakes sooner in your pedal stroke. If you do this, make sure push rod doesn’t bind in master cylinder bore. You might need to shim bottom bolts of booster bracket to tilt booster/MC up a bit if they are flat mount brackets.

Thanks will look into adjusting Clevis position