Hey my friend has a 94 integra 4 wheel disk, we recently replaced all teh pads, and a caliper, and blead the breaks, everything was fine untill we started to notice that at a light we would stop then the pedal would gradually sink to the floor, is this the master cylinder going bad? if so how hard to replace ive dont it on a ford f150, and an s-10, also how much do they run thanks mike

..also we checked everywhere for leaks and didnt find any.

 

Try re-bleeding the brakes. It takes about 6-8 tries to get it right.
Do them in a rotation until they feel ok:
PR
DR
PF
DF

D= drivers
P= passengers
R= rear
F= front

If this does not resolve the issue, then get your self a haynes manual at discount & test the master cylinder according to the manual & replace it accordingly etc..

 

probably master cylinder... mines doin the same thing and my master cylinder has a leak so i'll be replacing it soon... its not hard at all....