Help needed with LS7 clutch install - rock hard pedal - Page 2
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2004-2007 Cadillac CTS-V Performance Mods Discussion, Help needed with LS7 clutch install - rock hard pedal in Cadillac CTS-V Series Forum - 2004 - 2007; [Deleted following personal attack by moderation team that is inconsistent with published Cadillac Forum terms of use.]...
  1. #16
    FuzzyLogic is offline Banned
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    Re: Help needed with LS7 clutch install - rock hard pedal

    [Deleted following personal attack by moderation team that is inconsistent with published Cadillac Forum terms of use.]

  2. #17
    Derek5.7 is offline Cadillac Owners Member
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    Re: Help needed with LS7 clutch install - rock hard pedal

    And is that the adapter that has the valve that can get stuck and cause the fluid to get blocked?

  3. #18
    jmargo is offline Cadillac Owners Fanatic
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    Re: Help needed with LS7 clutch install - rock hard pedal

    Is the mechanic saying that when he opens the bleeder that the pedal stroke is now propper and fluid is moving ? If not tell him that you insist he disconnect the slave and make sure it is firmly seated. Not "it looks OK"

  4. #19
    FuzzyLogic is offline Banned
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    Re: Help needed with LS7 clutch install - rock hard pedal

    [Deleted following personal attack by moderation team that is inconsistent with published Cadillac Forum terms of use.]

  5. #20
    Derek5.7 is offline Cadillac Owners Member
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    Re: Help needed with LS7 clutch install - rock hard pedal

    Well, I got just got back from vacation and spent a 1/2 hour w/my mechanic and my car this afternoon. When you start the car up with the clutch pedal pressed down to the floor in first gear the car creeps forward, indicating the clutch is NOT fully disengaged (and if you try to let the clutch out it just stalls). So this much is clear: the clutch won't/isn't disengage fully, and, I should add, it is absolutely impossible to shift it into any gear with the clutch pedal pushed to the floor and the engine running. But here's the weird part - the pedal feels GREAT. A little stiffer/firmer than the LS6 clutch but not annoyingly so - I really like it, actually (feels worthy of a 400 plus HP engine). My mechanic says it just needs like 1/16 of an inch more "push" from the slave to fully disengage the clutch. So again, I have this dilemma - do I pay him the 5 hr shop time to (for a 2nd time) pull everything out again only to, most likely, discover the hardware is fine (flywheel, pressure plate, slave cylinder) or do I go with Philistine's new Master Cylinder upgrade which is more powerful than the stock MC and takes care of clutch disengagemenbt issues? Any help/suggestions would be greatly appreciated (and hopefully helpful to anyone else in the future who runs into this particular issue). I trust my mechanic when he says he feel very confident he put everthing in right (I would say mechanically there's not a lot to screw up with the basic hardware installation, especially from a guy that has done clutch upgrades MANY times).

  6. #21
    FuzzyLogic is offline Banned
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    Re: Help needed with LS7 clutch install - rock hard pedal

    [Deleted following personal attack by moderation team that is inconsistent with published Cadillac Forum terms of use.]

  7. #22
    ctsv247 is offline Cadillac Owners Enthusiast
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    Re: Help needed with LS7 clutch install - rock hard pedal

    So I'm guessing that the line wasn't pinched or the valve fuzzy referenced wasn't messed up.

    What was the pressure plate torqued too? For whatever reason, the ls7 pressure plate has a history of not working right in a v1 unless it's torqued to 48lbs which isn't the same torque spec as the ls7 corvette. If it was torqued to factory corvette ls7 specs, there has been many documented cases of it not working right...search it out.

    good luck

  8. #23
    Derek5.7 is offline Cadillac Owners Member
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    Re: Help needed with LS7 clutch install - rock hard pedal

    Okay, thanks Fuzzy - so I am NOT barking up the wrong tree to purchase/pursue one of Philistine's MC upgrade kits???? Thank-you for confirming that (and saving me (literally $$$) from having my mechanic tear everything apart again). Having FINALLY had a chance to sit in my car and experience this issue first hand I have to say the clutch feels absolutely awesome (very strong and NOT spongy - grippy BIG TIME) - and I NO longer have that AWFUL clunck/shudder on shut-down due to the duel mass flywheel AND it revs freely and quickly - WOW. So I'm just left with this clutch engagement issue and if Philisine's kit can remedy that (and confirm my suspicion that there is nothing wrong the with the LS7 clutch installation/hardware) I will be one happy camper!!!

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    CTS-247 - no, the clutch pedal felt great. I have to say my mechanic was a bit puzzled by my quizzing him on the torque specs for the pressure plate (he did it right/according to GM specs for both the flywheel and pressure plate) but he said the bolts on the pressure plate are torqued "metal to metal" so he was puzzled as to what the difference in torque could really do to the pressure plate "fingers." Details that are beyond me, I will admit, but he did show me what the pressure plate bolts up against and it was indeed "pure steel/metal" so I honestly don't know how those fingers could "sense" what torque the bolts had been torqued to. He had a point. Anyway, regardless, he torqued both the pressure plate and the flywheel according to spec.

  9. #24
    ctsv247 is offline Cadillac Owners Enthusiast
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    Re: Help needed with LS7 clutch install - rock hard pedal

    Quote Originally Posted by FuzzyLogic View Post
    So you can press the clutch pedal now? That sounds very different from the situation that you described earlier.

    A "correctly installed" LS7 clutch kit exists in a preloaded condition all the time, due to the CTS-V's shorter bell housing. While this is normally a major "no-no" when installing clutches (you're supposed to have a 0.050-0.125" gap), our OEM master cylinder is not powerful enough to actuate the LS7 clutch through more than about half of its full, 0.700" range of motion. I discovered several years ago that reducing the torque on the pressure plate bolts from the OEM spec of 52 ft-lbs to 48 ft-lbs would allow the pressure plate fingers to extend slightly and provide just enough additional preload to get the clutch disengaging. However, because of the weak MC, it will still be unreliable and require perfect bleeding procedures. Expect high RPM lockout, lots of double pumping as the system heats up, and notchy/hard shifting. To slightly improve the situation, you can also install one of Tick's 0.055" shims behind the slave.

    But these are really just bandaids. To get the clutch to work correctly, you need Philistine's Tilton 76-875 adapter, and you should remove the clutch pedal assist spring. Night and day difference.
    So what I'm reading is that you're suggesting that installing Philistine's clutch master kit is going to be another way to fix clutch dragging issues that were previously addressed by checking the installed depth of the throwout bearing and shimming accordingly?

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    Quote Originally Posted by Derek5.7 View Post
    [/COLOR]CTS-247 - no, the clutch pedal felt great. I have to say my mechanic was a bit puzzled by my quizzing him on the torque specs for the pressure plate (he did it right/according to GM specs for both the flywheel and pressure plate) but he said the bolts on the pressure plate are torqued "metal to metal" so he was puzzled as to what the difference in torque could really do to the pressure plate "fingers." Details that are beyond me, I will admit, but he did show me what the pressure plate bolts up against and it was indeed "pure steel/metal" so I honestly don't know how those fingers could "sense" what torque the bolts had been torqued to. He had a point. Anyway, regardless, he torqued both the pressure plate and the flywheel according to spec.
    http://ls1tech.com/forums/cadillac-c...ate-bolts.html

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    What fuzzy is saying makes sense but to my knowledge, you will be the first to use Philistine's clutch master kit to directly cure clutch dragging issues. I have one on order because I believe it will improve shift quality under high rpm loads shifting rapidly through the gears where the stock master can't keep up but you'd be a bit of a pioneer here if you go into the clutch master install with the impression it's going to fix your problem.

  10. #25
    Derek5.7 is offline Cadillac Owners Member
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    Re: Help needed with LS7 clutch install - rock hard pedal

    Philistine told me a couple of guys have used his MC to address my issue and it worked, so we shall see. And I will happily report back to this group on whether or not this works in my particular case. I feel this is the best path forward in my particular predicament. If the upgraded MC doesn't end up helping, I will still view it as a step forward in that I want to do this upgrade anyway (proven to remove shifting notchiness, etc.) and I will then move on to the next (more expensive) issue/path which would be to identify bad GM parts and/or incorrect installation of the LS7 clutch kit.

  11. #26
    ctsv247 is offline Cadillac Owners Enthusiast
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    Re: Help needed with LS7 clutch install - rock hard pedal

    it'll be money well spent. definitely report back for future reference.....good luck!

  12. #27
    FuzzyLogic is offline Banned
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    Re: Help needed with LS7 clutch install - rock hard pedal

    [Deleted following personal attack by moderation team that is inconsistent with published Cadillac Forum terms of use.]

  13. #28
    Derek5.7 is offline Cadillac Owners Member
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    Re: Help needed with LS7 clutch install - rock hard pedal

    Fuzzy, I really do appreciate you taking the time to explain the challenges (for some of us) asscociated with the LS7 clutch swap. I read the link provided by ctsv-247 and the issues/challenges are truly mind-numbing and potentially very costly and frustrating. I will report back after I have my mechanic install Philistine's MC upgrade.

  14. #29
    FuzzyLogic is offline Banned
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    Re: Help needed with LS7 clutch install - rock hard pedal

    To AAIIIC and the rest of the moderation team:

    Silently deleting a paragraph talking about "VSF" (VSeriesForums), LS1Tech, or any of the other competing forums is not consistent with your published terms of service. Because you only seem intent on blocking people from mentioning VSF and not your other competitors, I can only conclude that these silent edits are personal attacks.

    Bottom line: are you going to moderate or not? Do you consider yourself above the rules? Every time you utilize your software privileges to exercise your personal problems on others, you're driving subject matter experts (like me, with respect to clutch design, set up, and operation) away.

  15. #30
    jmargo is offline Cadillac Owners Fanatic
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    Re: Help needed with LS7 clutch install - rock hard pedal

    Sounds like it just needs more bleeding.

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