New front and rear calipers/cylinders. New master cylinder. Bled brakes over and over again. No air anymore, so clearly well bled. Bench bled the MC first.
Car doesn't stop worth a .....
What happens is that the pedal will be soft for the first bit, then gets real hard as it closer to the bottom. Rear brakes will lock or get hot but front brakes hardly getting warm. Clearly poor front brakes. Almost all stopping comes from the rear brakes.
Doesn't make a difference whether the vacuum line is on or off of the booster. With the booster working, the pedal pulls faster through the first part of the pedal than when the booster vacuum line is disconnected. With or without the booster, the pedal gets hard close to the bottom of travel.
Ideas??

 

Clogged balancing block/proportioning valve? (I am NOT a mechanic.)

 

Stock porportioning valve removed and replaced with rear only porportioning valve.

 

Are you the guy that was asking which line on the master cylinder goes to the front/rear?
If you got that mixed up that might explain your problem.

 

Long story short.. two bad remanufactured master cylinders.. Bought a new master, bench bled, installed and brakes bled in 5 minutes and brakes perfect.. Go figure...