brake problems

:banghead:i recently installed a new front rotor and caliper on my 96 grand prix. i drove it about two days then all a sudden my brakes would come and go. Took it home and the high pressure line on the caliper was loose. tightned it up bled it then same thing happened again but the line was tight this time. I have been bleeding it for about 3 hours with no luck. did what the book said to do step by step but the front line where i had the line come loose will not bleed. Constantly has air. no other line has a problem. what could it be? :banghead:

does the brake pedal sink to the floor or does it stay up when holding constant pressure?

sometimes there is alot of pressure other times there isnt.the peddle will go almost all the way to the floor when there isnt much pressure. its hit or miss. im going nuts.

sounds like a bad master cylinder to me.

assuming, you checked the brake lines...

well its just odd that the line came loose from the caliper and the master cylinder go bad at the same time.

I agree, are you sure the copper washer is installed and installed in the right direction?

Are you bleeding from the brake farthest away from the master cylinder to the one thats closest? passenger rear, driver rear, passenger front, driver front?

Good call TIm. I didn't even think about the copper washers. There should be one on each side of the hose. If they are not there, the hose can come loose, and it will suck air due to a bad seal causing a low pedal and no brakes.

If the washers are both there and the hose is still tight, I agree that the master cylinder is bad.

yes the washers are both there and brand new and installed correctly. i bled the car exactly by the book and that one line is the only one im having trouble with.

Have you watched the hose while someone else pushes the brake pedal? The hose may be ballooning due to an internal break in the kevlar lining that gives it it's strength.