the brake master cylinder is going bad. when i push on the brake, it almost reached the floor. i think its probably old and worn out. what should i do? should i replace it? or could it be the result of bubbles in the brake lines? what do you think?

if i need to replace it, how hard is this? how much does the part usually go for? this is for a 90 integra LS

 

Try bleeding it. If it doesn't work, then replace. $60 from Autozone.

 

If you pump it a few times does it raise the pedal somewhat... if it does defintely the master cylinder on it's way out... replace it.

If the pumping does not raise the pedal it may be air in the line, try bleeding.

 

In my experience it's been the other way around.

Air in the lines... Mushy pedal at the very beginning, pump it & it gets better.

Bad MC... Brake pedal is hard, but then slowly & smoothly sinks.

 

if there is liquid on the driver site floor or the pedal goes to da floor while braking, then u need to replace it