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1G Clutch and Slave Cylinder diagnosis

Posted by ATXDSM, Feb 10, 2019

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  1. ATXDSM

    ATXDSM Probationary Member

    4
    0
    Joined Aug 22, 2017
    Austin, Texas
    Trying to figure out my clutch problem. Clutch pedal is adjusted up properly and the master cylinder adjustment is near maxed out. When I push the slave cylinder in by hand, the slave depresses all the way in and when I let go, it does not extend back out. It barely extends back out leaving the clutch fork loose. To get the pressure back up I have to press the clutch pedal down in which it sticks to the floor. I have to pick the pedal back up by hand then press down again and the pressure is back. The clutch fork sits right in the middle and there is no leaks from the master cylinder and slave cylinder. It has a new XACT Streetlite Flywheel and ACT 2100 with solid street disc installed with OEM TB that has only seen idle time and a brief drive around the block. The system has been bled as well. Ive searched many threads and cannot find a definitive answer
     

    108  1

    1991 Eagle Talon TSi
    fwd · manual · 1G DSM
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  2. DSMPT

    DSMPT Proven Member

    317
    81
    Joined Jun 12, 2014
    Mexico, Arizona
    Sounds like worn out piston in master or slave cylinder. Replace cylinders with new or rebuild if still within spec. I recommend you to replace the both of them with new at the same time.
     

    Street Build 684  2

    1998 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM

    Drag Race Build 506  1

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM
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    tametalon92 likes this.
  3. ATXDSM

    ATXDSM Probationary Member

    4
    0
    Joined Aug 22, 2017
    Austin, Texas
    I was thinking the same thing but wanted another opinion before I threw some parts at it.
     

    108  1

    1991 Eagle Talon TSi
    fwd · manual · 1G DSM
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  4. DSMPT

    DSMPT Proven Member

    317
    81
    Joined Jun 12, 2014
    Mexico, Arizona
    I had exactly the same issue when I upgraded the clutch from old stock one. I rebuilt the cylinders but didn't last long. After I replaced the both of them with new OEM, the issue was solved.
     

    Street Build 684  2

    1998 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM

    Drag Race Build 506  1

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM
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  5. ThunderChild

    ThunderChild Previously tametalon92

    1,719
    378
    Joined Jan 5, 2012
    Rathdrum, Idaho
    Agree with @DSMPT, sounds like an internal master leak, or air in the line more likely. May even be leaking into the booster itself.
     

    Street Build 311  7

    1997 Mitsubishi Eclipse Spyder GST
    fwd · manual · 2G DSM

    Street Build 566  1

    1992 Eagle Talon TSi AWD
    manual · 1G DSM

    Street Build 1K  10

    1992 Eagle Talon TSi AWD
    awd · manual · 1G DSM
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  6. pauleyman

    pauleyman DSM Wiseman

    4,949
    882
    Joined Nov 19, 2011
    oklahoma city, Oklahoma
    Booster???
     

    Street Build 2K  1

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
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  7. ThunderChild

    ThunderChild Previously tametalon92

    1,719
    378
    Joined Jan 5, 2012
    Rathdrum, Idaho
    From the master cylinder into behind the booster diaphragm, hence why he wouldn't see leaks, but still having issues. Have seen a couple threads in the past year where this was discovered as the issue after investigations. Just a thought
     

    Street Build 311  7

    1997 Mitsubishi Eclipse Spyder GST
    fwd · manual · 2G DSM

    Street Build 566  1

    1992 Eagle Talon TSi AWD
    manual · 1G DSM

    Street Build 1K  10

    1992 Eagle Talon TSi AWD
    awd · manual · 1G DSM
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    iugrad92turbo likes this.
  8. tk106

    tk106 Proven Member

    738
    85
    Joined Sep 11, 2017
    Cincinnati, Ohio
    Take the hose off the booster and stick a long zip tie down the hole. You will see fluid on the tip of the zip tie if it's leaking internally.
     

    Street Build 1K  8

    1992 Eagle Talon TSi AWD
    awd · manual · 1G DSM
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    tametalon92 likes this.
  9. pauleyman

    pauleyman DSM Wiseman

    4,949
    882
    Joined Nov 19, 2011
    oklahoma city, Oklahoma
    We're talking about a clutch. So again....booster?
     

    Street Build 2K  1

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
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  10. tk106

    tk106 Proven Member

    738
    85
    Joined Sep 11, 2017
    Cincinnati, Ohio
    Haha. Sorry. I had brake master in my head for some reason. Prob because I replaced clutch master, slave and brake master recently.

    Op. Have you had the clutch line open recently? If so, most likely you have air in the system. If not, replace both master and slave. They’re fairly cheap from rock auto.
     

    Street Build 1K  8

    1992 Eagle Talon TSi AWD
    awd · manual · 1G DSM
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  11. ThunderChild

    ThunderChild Previously tametalon92

    1,719
    378
    Joined Jan 5, 2012
    Rathdrum, Idaho
    And so did I... brain fart. Thanks for the catch @pauleyman
     

    Street Build 311  7

    1997 Mitsubishi Eclipse Spyder GST
    fwd · manual · 2G DSM

    Street Build 566  1

    1992 Eagle Talon TSi AWD
    manual · 1G DSM

    Street Build 1K  10

    1992 Eagle Talon TSi AWD
    awd · manual · 1G DSM
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