Brake Feel. MC? Booster?

[73fj55]

My 69/77 hybrid pig has a real soft pedal, almost like you cannot feel anything so you push harder and harder and then all of the sudden BOOM they engage. I have tried to bleed the brakes, numerous time to see if that was the issue and it is not. I have also tried to monkey with the pedal to booster rod,(adjusting nuts) nothing. So I am wondering if it isn't my MC or Booster. When I push on the brakes as I am starting it up I feel the pedal move in slightly. Good? Bad?

If I do need to change the booster what problems will I run into; it being a 69 I believe that I have a 3 bolt pattern instead of a 4 bolt. The 3 bolt boosters look smaller/thinner then the 4 bolt. Any difference?

thanks for the help.

 

[LC_Hamma]

The slight pedal movement would be the engine vacuum activating the booster. I have experienced that pedal movement upon startup before. Do you hear any air leakage from the booster at all? It could also be a vacuum leak somewhere else, but I'm guessing now.

 

[cruiser_guy]

Disc brakes? Have you adjusted the brakes recently? OEM '55 brakes are not self adjusting like a newer vehicle.

 

[73fj55]

Disc brakes? Have you adjusted the brakes recently? OEM '55 brakes are not self adjusting like a newer vehicle.

69 body with a 77 drivetrain. Front disc and rear drum.

I have gone through the whole system many times. I have searched and everything seems to be pointing to a bad MC. Since I do not know the story of the whole rig or how old any of the parts are I will try there first.....

wish me luck

 

[cruiser_guy]

OK, 'cause mis-adjusted brakes make the pedal go to the floor and sometimes it'll need two pumps to stop. All due to the pistons in the wheel cylinder needing to extend too far.

 

[cardinal fang]

Do you have the 66 brake master in it, or the 77?

 

[73fj55]

I have the 69 booster in it. That is what was in it when I purchased it.