I have a 1968 cougar xr-7 that I am restoring for my first car. I installed a new booster and master cylinder and I am still having issues braking. When I apply pressure on the pedal I feel the power brakes work and the car begins to stop easily. Then the pedal goes a little more than half way down and it releases the power brakes and I have to push very hard to make the car stop. It’s almost like it goes back to manual brakes. I don’t know what I should do. Any advice?
Sounds like maybe you still have air in the lines. I would bleed them at all four corners again.
Is this the same problem you were having before replacing the MC and the booster?
Okay I will try to bleed the brakes a few more times and see how it goes. And this is a restoration, the car was sitting for 20 years and the booster and mc didn’t even work. So no I haven’t had this problem before. Thanks for the help guys, ill see if it works!
If it’s been sitting that long and you haven’t bleed every drop out to get the rust out (the lines rust from inside out), and rebuild the wheel cylinders/calipers you are fighting a losing battle most likely. Seriously consider replacing the lines if you see rust/gunk/crap coming out. Once rust starts in the lines it continues to cause grief anyways…if the car has drums buy a rebuild kit and a brake cylinder hone. Open it up - hone it out, then put it all back together and bleed it out. You won’t have hanging brakes due to the cylinders getting caught up in the gunk…
I replaced the whole brake system. Lines, cylinders, calipers, mc, and booster. It’s just having problems now.