I am having a problem with my brakes. I own a 1995 Chevy Z-71 and have already replaced the mastercylinder with no fix. When I step on the pedal, it slowly goes to the floor. Please Help!!!

 

did you bleed thr brakes? kind of sounds like you brake booster check to make sure vaccum line going from TBI to brake booster is not cracked and leaking

 

my ole man had a problem like that with a less than 1 year old 99 classic body 1500 it did the same thing .the dealer could not fix it ,he ended up making chevy and the dealer buy it back .he worked at a gmc truck dealer and could access gm warranty issue's online buy vin # and the last thing done to the truck was to replace a brake caliper ? simple thing .

 

Normally, if you are not losing brake fluid, you likely have a seal problem in the master cylinder. Its seeping past the seal back into the reservior. But, since you have replaced the master cylinder, I think its likely that you have a messed up ABS unit, a massive amount of air in the line close to the master cylinder, or you have a bulging hose.

If you are losing fluid, I'm going with the guys on this one and saying that there is a caliper piston seal broken.

 

I HAVE SWAPPED THE MASTER CYLINDER ABOUT THREE TIMES AND IT DOES THE SAME THING. tHE ONLY THING THAT I'M NOT SURE OF IS THE ABS BOX UNDER THE HOOD. COULD THAT CAUSE THE PROBLEM? I DON'T MIND THE PRICE BUT I DON'T WANT TO CHANGE IT IF IT WILL NOT FIX MY PROBLEM. THANKS FOR YOUR HELP.

 

I have bleed the brakes and the master cylinder to. Me and another mechanic has been working on this in our spare time. Thanks for your help.