I just replaced a wheel cylider and and bled the brakes. when I took the car for a test drive the pedal is still squishy and when stopped at a light it will slip and move doen without any added pressure. If I wouldn't allow it to move sown the car would roll. I bled the brakes again but not much air came out, just a few bubbles. I went for a test drive but I still have the same proble. Is the problem in the master chylinder. I think that maybe a seal is bad and when the pressure builds up in the cylider it allows the fluid to flow past the seal and I lose brake pressure. Thanks in advance.
Sounds like you have a bad master cylinder. If you are sure that you bled all of the air out, then look around the master cylinder for leaks. The best dead give-away of that is if you see paint peeling from behind the master, (brake fluid eats paint). If not there, check around your wheels for wet spots.
Is it possible that there is an internal leak and that it cant hold pressure and that is why the brakes get loose? I haven't noticed and leaks outside the cylider or at the wheels.
More likely you were not as thorough as you should have been in your brake
bleeding. If the master cylinder was fine before you replaced the wheel
cylinder, why do you think it went bad while you were doing your repair?
Which cylinder did you replace? You should go through the whole brake bleed procedure again on every wheel cylinder. Start with passenger back, driver back, passenger front, driver front.
And this would be really silly but...... did you make sure to fill your reservoir back up? While your bleeding the brakes, make sure the level doesn't fall to expose the bottom. Otherwise you might as well start the whole thing over again. :banghead: