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Brake Pressure Sinks with First Pump of the Pedal

Discussion in 'Wheels / Suspension / Tires / Brakes' started by MarkJimenez99, Jan 2, 2004.

  1. MarkJimenez99

    MarkJimenez99 Senior Member

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    I need your help again, guys. Let me explain to you my situation. When I'm driving my car and I push on the brake once, it sinks almost all the way to the floor. It doesn't feel like my brakes are working to its full potential with the first pump of the brake pedal. I own the front Wilwood Brakes. Here's the weird part, if I pump on it a few times, the pedal pressure builds which is exactly how I want my brakes to feel every time I step on the brakes. I didn't have this problem before I swapped my clutch in.

    When the car is off and I pump my brakes, pressure builds and they have a nice, firm pedal feel and not spongy. I checked for leaks and there weren't any. It doesn't seem like there are any air bubbles in the system. Well, I could be wrong, that's why I'm asking you guys. Do I need to re-bleed? What do you think the problem is or do I even have a problem?

    I would appreciate your input on this. Thanks.
     
  2. moto27cm

    moto27cm Junior Member

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    It sounds like you need to bleed them once more. I always end up bleeding mine twice, need it or not, just to be safe. Many times, air will surface under a little bit of use. Make sure to start at the right rear, then do left rear, then right front, then left front.

    I would also check out your booster to make sure your not loosing vaccum.

    If all else fails, you may need a larger M/C. Im not positive about that though, as I havent used the Wilwood kit.
     
  3. asmallsol

    asmallsol Super Moderator

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    sounds like a interior leak in the master cylinder.
     
  4. MarkJimenez99

    MarkJimenez99 Senior Member

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    Interior leak? How do I check for that? I checked the master cylinder and I'm not losing any brake fluid. Like I said, I didn't have a problem with my brakes before I installed my clutch. Perhaps some air got into the ss lines because the hub assembly was kinda hanging from them. :unsure: I know I shouldn't have done that, but it's too late.

    I will rebleed the brakes. Other than that, anymore suggestions?
     
  5. xj0hnx

    xj0hnx I wanna be sedated VIP

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    Could also be losing the vacuum in the booster.
     
  6. moto27cm

    moto27cm Junior Member

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    -->
     
  7. MarkJimenez99

    MarkJimenez99 Senior Member

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    Ok, so how do I check my booster to see if I'm losing vaccum?
     
  8. moto27cm

    moto27cm Junior Member

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    Click here.

    You probobly only need to bleed your system though.
     
  9. K2e2vin

    K2e2vin Senior Member

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    then the brake pedal would be hard to pump.
     
  10. pissedoffsol

    pissedoffsol RETIRED

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    master cyl's are shitty...

    sometimes, they get USED to their pedal "distance". when you bleed, and push it to the floor, you disrupt its normal course. it then springs a leak.
    happened to me, and bill says its very common.

    try to pick up a used gsr master cyl (if you have a civic) for a little more umph... hit up the junkyard or somethign
     
  11. MarkJimenez99

    MarkJimenez99 Senior Member

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    I just re-bled the system. It feels a little better, but not how I would want it to be. I didn't find any leaks. I'll probably just replace the master with a better one. Thanks for the advice guys.
     
  12. asmallsol

    asmallsol Super Moderator

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    I believe that you need to replace the brake booster with the GSR one when you put the GSR master cylinder on.
     
  13. K2e2vin

    K2e2vin Senior Member

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    could be brake lines, it may be stretching when the pressuer goes up..
     
  14. MarkJimenez99

    MarkJimenez99 Senior Member

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    I have ss brake lines
     
  15. 89_starter

    89_starter Member

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    I put new calipers and rotors on and I still had a sloppy pedal, it turns out is was only a matter of replacing the booster hose. 3/8 from work 1.20 a foot!
     
  16. MarkJimenez99

    MarkJimenez99 Senior Member

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    Cool, I think I'm gonna try that. Thanks.
     
  17. xj0hnx

    xj0hnx I wanna be sedated VIP

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    Yes you do, they bolt on backwards from the civic ones. But the RS and 91 EX ones are the same
     
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