hellow new member here with trouble. i have a 1988 honda civic lx. my brakes when first started are working fine but as soon as i start to use the brakes they get tight and cannot push down the petal at all. i have changed the calipers, pads, the proportional valve, the booster, and lines. i have bought it to 3 mechanics and nothing. please help.

 

Could it be a problem with the master cylinder? Perhaps the internal piston mechanism is faulty?

 

have you changed the brake fluid? How does the engine run when you press on the brake pedal? does it bog down and want to die or doenst do anything?

 

the master cylinder is brand new. no i haven't changed the fluid. the engine bogs down when i press the brake. it locks up so bad it smokes and can't even touch the rim.

 

did you put the right proportioning valve in it?

 

Have you tested the check valve for proper function (see picture)?

 

alright..are you saying that your brakes seem to be working fine....then after driving for a little bit they begin to lock up until you can't move your car?