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CDV, in or out?

Discussion in 'Z3 Roadster & Coupé' started by lightning, Jul 25, 2014.

  1. lightning

    lightning Zorg Legend

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    I removed the clutch delay valve from my Z3 3.0
    It did stop the momentary clutch slip on fast gear changes.
    But it also made it very difficult to get a smooth gear change from first to second under "normal" driving, without shunting.
    So l refitted the CDV and it was smooth again.
    Swings and roundabouts l guess. Remove one issue and create another.
     
  2. GazHyde

    GazHyde The Gaz Monkey
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    How did you remove it? Usually fitting an Earls braided clutch hose with CDV delete usually works really well. Still have it on my to do list so not experienced it first hand.

    I know @Titan had one fitted on his...
     
  3. lightning

    lightning Zorg Legend

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    On my car the CDV is on the end of the flexible hose, where it joins the slave cylinder steel pipe.

    You can remove it and then reconnect the hose directly to the pipe.
    Then bleed the system and off you go. Takes ten minutes (having a Sealey pressure bleeder makes the job much easier)
     
  4. GazHyde

    GazHyde The Gaz Monkey
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    Yes I believe there are a couple of types of hose, but wasn't aware of one which it can removed from. Learn something new every day :)
     
  5. vintage42

    vintage42 Dedicated Member
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    I don't know what shunting is. I have always shifted with deliberation, in consideration of the synchros, on every car I have had. I recently replaced my original clutch hose with a braided hose:
    http://store.uucmotorwerks.com/stai...6-318iisti-all-z3-mz3-incl-s52--s54-p318.aspx
    It slightly raised the clutch engagement point.
     
  6. lightning

    lightning Zorg Legend

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    Without the CDV fitted l found it very difficult to match the RPM to speed when changing from first to second gear, and to a lesser extent, second to third, under normal driving (not driving the car particularly fast or slow)
    The car would lurch or "shunt" as l let up the clutch, no matter how carefully l tried.
    With the CDV fitted it is a lot smoother, and l can get a lurch free gear change.
    The actual clutch seems fine, engaging about a third of the way up the travel of the pedal.
    I already replaced the gearbox oil, which did improve the general operation of the transmission.
     

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