Soft brake pedal....
Thread Starter
Instructor
Joined: Apr 2013
Posts: 116
Likes: 0
From: Liverpool New York
Soft brake pedal....
First of all, the car is up on stands....that may or may not be a factor in this problem.
I have re-installed my rear calipers and have gone through the bleeding process twice with DOT 3. the first was with a helper and we fully cycled new fluid though all four calipers....pedal soft. The second I did alone...opened each bleeder individually and let gravity do its work, again cycled a large amount of fluid out and new fluid in and the pedal is still soft.
The master cylinder has been bled and I'm sure there is no air trapped in the lines.....
Now I'm thinking maybe the problem is with the booster, but I have no idea how to test this.
Does anyone have any suggestions on what to do next?
Thanks
I have re-installed my rear calipers and have gone through the bleeding process twice with DOT 3. the first was with a helper and we fully cycled new fluid though all four calipers....pedal soft. The second I did alone...opened each bleeder individually and let gravity do its work, again cycled a large amount of fluid out and new fluid in and the pedal is still soft.
The master cylinder has been bled and I'm sure there is no air trapped in the lines.....
Now I'm thinking maybe the problem is with the booster, but I have no idea how to test this.
Does anyone have any suggestions on what to do next?
Thanks
Drifting
Joined: Aug 2005
Posts: 1,372
Likes: 4
From: Springfield VA
Booster usually causes a very hard pedal, you lose power brakes.
What I did was run clear lines from the bleeds valves to above the car. Opened the valves and pressed on the pedal lightly. The air will rise while the fluid will stay in the caliper. I did this trick when I was a tech on cars that were hard to bleed.
After that look at the seals on the calipers to see if there is any wetness/leaks. Next make sure the brake hoses are not bad. Then if all of that is 100% good then look at the master cylinder.
What I did was run clear lines from the bleeds valves to above the car. Opened the valves and pressed on the pedal lightly. The air will rise while the fluid will stay in the caliper. I did this trick when I was a tech on cars that were hard to bleed.
After that look at the seals on the calipers to see if there is any wetness/leaks. Next make sure the brake hoses are not bad. Then if all of that is 100% good then look at the master cylinder.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
I am a fan of pressure bleeding. It has never failed me yet.
Often times when I am doing a complete brake system...new everything... and the lines were flushed out. When I install the parts and pressure bleed the car...I also use an air hammer to shock the frame in a safe spot so it will release any air bubbles stuck to the inner side of the lines. Then I might pressure bleed it again the next morning.
DUB
Often times when I am doing a complete brake system...new everything... and the lines were flushed out. When I install the parts and pressure bleed the car...I also use an air hammer to shock the frame in a safe spot so it will release any air bubbles stuck to the inner side of the lines. Then I might pressure bleed it again the next morning.
DUB
Thread Starter
Instructor
Joined: Apr 2013
Posts: 116
Likes: 0
From: Liverpool New York
It's amazing what we can accomplish when we do things correctly! I never bled the inside bleeders....don't know what I was thinking....or not thinking. Problem Solved!
Thanks
Thanks
