Brake HELP
Thread Starter
Racer
Joined: Feb 2005
Posts: 327
Likes: 1
From: Higgins Lake Michigan
Brake HELP
Need help with with my son's 69 vette. We have put all new rotors, calipers, pads and lines on his 69 last fall. Have bleed the brake system 3 times. Stll , brakes are not good. When you push on the brake pedal it sticks and have to put your toe under the pedal and pull it back up. Not a good brake pedal ( stopping at any time ). We did not change the master cylinder or the brake booster. We need help. Any idea's what the problem is ???? Thnx Dave 
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
You do still have some issues and there may be more than one. First, check the brake pedal return spring. It's at the top of the brake pedal at the assembly.
Next, test the booster. With the engine off, pump the pedal. It should get hard after a few pumps. Then start the car, it should go soft under your foot.
If it doesn't get hard, then you may have a bad booster. If it doesn't go soft then you might have a vacuum leak.
Masters can go bad, and they are easy to rebuild. It's a cheap kit and you can do it in about 30 minutes.
Next, test the booster. With the engine off, pump the pedal. It should get hard after a few pumps. Then start the car, it should go soft under your foot.
If it doesn't get hard, then you may have a bad booster. If it doesn't go soft then you might have a vacuum leak.
Masters can go bad, and they are easy to rebuild. It's a cheap kit and you can do it in about 30 minutes.
Race Director
Joined: Jul 2004
Posts: 12,705
Likes: 329
From: Scottsdale Arizona
If your pedal won't come back on its own, the master cylinder likely needs to be replaced. Not sure that I ever heard of the spring in there failing so if it has, the seals are almost certainly shot too.
Replace the M/C and see if that helps. Remember to bench bleed the M/C according to the instructions in the box. You'll also have to rebleed the calipers as you'll trap some air by undoing the line fittings.
Replace the M/C and see if that helps. Remember to bench bleed the M/C according to the instructions in the box. You'll also have to rebleed the calipers as you'll trap some air by undoing the line fittings.
