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Thread: Long pedal after new calipers- multiple bleeds

  1. #1
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    Long pedal after new calipers- multiple bleeds

    Replaced all 4 calipers (nice "new" calipers from Eric) and pads on my '72 T targa. Even after multiple bleeds with Motive and another with a friend the old fashioned way, still have a really long pedal with horrible feel. Not getting any air out but pedal won't firm up. Pedal feel was great before I started...
    I've been doing this for 40+ years but what am I missing????
    1971 914- original owner
    1973 914 2.0
    1972 911T targa
    2016 981 spyder
    2014 turbo S coupe
    2019 RS5 sportback

  2. #2
    Did you put new rotors on also? Drive it a couple hundred miles, then see what it feels like. What did Eric say to do?
    Early S Registry member #90
    R Gruppe member #138
    Fort Worth Tx.

  3. #3
    Are the calipers new, or rebuilt by PMB? If rebuilt, I had an experience with PMB rebuilt calipers where plastic media (BB's of sort) were left behind in the fluid channels during the assembly process, and until I discovered this, no amount of bleeding would produce anywhere near a good pedal. Hope it works out. P.S. Eric did right by me in this case - compensating me for $$ spent in having my early 911 tech do a house call - we bled, and bled some more and even changed the master cylinder until finally going into the calipers where the issue was discovered. Hope you resolve your problem without that much hassle.

  4. #4
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    I recently did the front brake rebuild- new piston gasket and seals- and had the same problem. It seems like the new dust seals are sufficiently stiff that they pull the pistons back after releasing the pedal. I solved it by putting a pole between the brake pedal and the seat back to stretch the seals out overnight. That worked. I'm sure they will loosen up with time naturally, but it is disconcerting.
    Jeff Jensen

  5. #5
    Senior Member
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    Best way to fix them is to just drive the car. After a hundred or so miles your brakes will be just fine.

  6. #6
    Senior Member jim amato's Avatar
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    Yep, Went thru exact same scenario, calipers by eric,new master cyl, work done by Truman ent. was recommended to do same procedure as Mobius suggest, now after 800-900 miles brakes are superior, good stopping power, good pedal, drive It!
    registry #2072

  7. #7
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    Just talked with Eric and he said it is most likely the seal issue. Will bed in brakes to get them hot- not an issue here in Scottsdale this time of year!! Once seals and pads bed in pedal should come back...
    1971 914- original owner
    1973 914 2.0
    1972 911T targa
    2016 981 spyder
    2014 turbo S coupe
    2019 RS5 sportback

  8. #8
    This can also happen if the fr callipers are fitted upside down. Bleed nipples at the top.

    Hope you sort it.

    Alan

  9. #9
    Senior Member 62S-R-S's Avatar
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    Aside from seals, bleeding a whole system of 4 calipers, is a longer task than anyone might expect. Using compressed air @20 psi, which is a pretty good method...it's surprising to see time involved to get 100% normal pedal. Sometimes bubbles surface -- a couple days after a line demonstrated clear fluid. So it is a trickier job than changing a tire imo. For ex., on 4 piston Wilwood calipers, if opening and closing a bleeder nut several x's in succession, it bleeds better than just one open/close sequence, but not sure what the reason is for it.

  10. #10
    Early 911S Registry # 237 NeunElf's Avatar
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    Yep, get the brakes HOT to release the seals' grip on the pistons.

    I had the "seals problem" after rebuilding mine. The brake pedal went to the floor although the brakes would pump up.

    PMB's advice was to go out and do a series of panic stops to get them hot. I modified that and drove around the "block" (a bit over a mile) while dragging the brakes. The car reeked of hot brakes when it was back in the garage and the brakes worked fine.
    Jim Alton
    Torrance, CA
    Early 911S Registry # 237

    1965 Porsche 911 coupe
    1958 Porsche 356A cabriolet

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