Rebuilt Brake Caliper and...Pedal goes to the floor? |
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Rebuilt Brake Caliper and...Pedal goes to the floor? |
atomix8 |
Aug 16 2015, 11:14 AM
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#1
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Member Group: Members Posts: 73 Joined: 10-September 07 From: Annapolis, MD Member No.: 8,105 Region Association: MidAtlantic Region |
Have been battling this problem myself for a few weeks...and realizing I just missed the annual Northeast meet up, and am about to miss 2 more car shows... I think I have finally tried everything I can personally think of -- I need help!
Long story short, I hope: Front right caliper was dragging a little bit, figured I'd rebuild before it got worse. Took the caliper off and lost a bit of fluid, still plenty in the master cylinder. Had trouble getting the pistons out, so ended up using the "grease gun trick", not recommended but it worked. Cleaned up the caliper with tons of brake clean, put in new seals, pressed pistons back in, indexed them and bolted it back up. Then the saga of bleeding: 1. Did the "two man" brake bleeding method at first on just the rebuilt caliper...and couldn't get a hard pedal. 2. Did "2 man" on all 4 calipers -- pedal still soft. 3. Put on the Motive power bleeder, burst a hose on the motive...cleaned up a fountain of brake fluid 4. Actually bled all 4 with the Motive (new hose) -- pedal still soft. 5. Drove around the block, had to pump the brakes like heck to stop -- no change. 6. Had a friend 'pump up' the brakes and then 2 man bled the fronts -- no change. Other relevant facts: A. Before I started this adventure, I had a great hard pedal. B. Brake fluid squirts out of all calipers when I bleed, so I don't suspect a master cylinder issue (should I?) C. Rear brake pads are worn on one side, but seems unrelated...again pedal was great. So, what the heck am I forgetting?? (IMG:style_emoticons/default/confused24.gif) |
atomix8 |
Aug 16 2015, 12:16 PM
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#2
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Member Group: Members Posts: 73 Joined: 10-September 07 From: Annapolis, MD Member No.: 8,105 Region Association: MidAtlantic Region |
Appreciate the quick replies guys.
I had heard the "drive it hard" theory a few times here, but heck, I can barely stop...I'm not looking forward to going more than 20 mph! I will re-try banging all the calipers with a hammer...time to get it back in the sky on 4 jack stands I suppose. Are you recommending 2 man or pressure bleeding?? Mike (Cuda911) -- I tend to agree with ya...never had this much trouble bleeding brakes, but that's a famous 914 line as well. RE: the master cylinder, it is old, but is some OEM brand, not URO. Trying to avoid replacing that as part of trouble shooting. |
Bartlett 914 |
Aug 16 2015, 01:13 PM
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#3
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Advanced Member Group: Members Posts: 2,216 Joined: 30-August 05 From: South Elgin IL Member No.: 4,707 Region Association: Upper MidWest |
Appreciate the quick replies guys. I had heard the "drive it hard" theory a few times here, but heck, I can barely stop...I'm not looking forward to going more than 20 mph! I will re-try banging all the calipers with a hammer...time to get it back in the sky on 4 jack stands I suppose. Are you recommending 2 man or pressure bleeding?? Mike (Cuda911) -- I tend to agree with ya...never had this much trouble bleeding brakes, but that's a famous 914 line as well. RE: the master cylinder, it is old, but is some OEM brand, not URO. Trying to avoid replacing that as part of trouble shooting. I have never had this problem with a master cylinder but I have read that pushing the pedal to the floor can damage the master cylinder. Normally this never happens. When the fluid is changed and you press to the floor the seal in the MC gets into a place it normally doesn't go and the seal could be damaged. I think you still have air in the lines however. When bleeding I like to connect a clear tube and run it vertical as much as possible. This makes it easier to see bubbles. I also press the pedal quickly. This helps move air down the line better |
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