Clutch Hydraulics
01-04-2008, 01:26 PM
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I haven't found any discussion on this topic in the FAQs or anyplace else, so here goes. I have a 545i, 6 speed, and the clutch actuation is difficult to get smooth due to the restriction from the check valve in the clutch hydraulics. BTW, I have 25 years of driving manual shift cars. The check valve was intended to keep people from dumping or banging the clutch (and it works) but it also inhibits smooth shifting and even encourages slipping the clutch to get a smooth shift. Bav Auto has a free flow valve ($29.95) that replaces the factory installed check valve and purports to give me back my smooth shifting. I understand why BMW put the check valve in the line in the first place but I hate the **** thing. Has anybody else experienced the shifting probs that I have and has anyone tried the Bav Auto free flow valve?
01-04-2008, 01:53 PM
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My Ride: 2006 530i - Sport - 6spd - Orient Blue with Auburn/Anthracite
I had mine replaced with the modified valve from Zeckhausen Racing - it made a difference, but I wouldn't call it a "night and day" difference, more like a subtle but positive improvement...
Good Luck!
Good Luck!
Originally Posted by gretamay' post='513762' date='Jan 4 2008, 03:26 PM
I haven't found any discussion on this topic in the FAQs or anyplace else, so here goes. I have a 545i, 6 speed, and the clutch actuation is difficult to get smooth due to the restriction from the check valve in the clutch hydraulics. BTW, I have 25 years of driving manual shift cars. The check valve was intended to keep people from dumping or banging the clutch (and it works) but it also inhibits smooth shifting and even encourages slipping the clutch to get a smooth shift. Bav Auto has a free flow valve ($29.95) that replaces the factory installed check valve and purports to give me back my smooth shifting. I understand why BMW put the check valve in the line in the first place but I hate the **** thing. Has anybody else experienced the shifting probs that I have and has anyone tried the Bav Auto free flow valve?
01-04-2008, 04:36 PM
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I think most people here call it the "clutch delay valve" or CDV. If you put the letters "CDV" into the Google search at the top of this page, you'll likely get a bunch of hits. Also, put "clutch delay" in there after you're finished with the first results and you'll likely get some other posts...
01-04-2008, 05:10 PM
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Originally Posted by gretamay' post='513762' date='Jan 4 2008, 05:26 PM
I haven't found any discussion on this topic in the FAQs or anyplace else, so here goes. I have a 545i, 6 speed, and the clutch actuation is difficult to get smooth due to the restriction from the check valve in the clutch hydraulics. BTW, I have 25 years of driving manual shift cars. The check valve was intended to keep people from dumping or banging the clutch (and it works) but it also inhibits smooth shifting and even encourages slipping the clutch to get a smooth shift. Bav Auto has a free flow valve ($29.95) that replaces the factory installed check valve and purports to give me back my smooth shifting. I understand why BMW put the check valve in the line in the first place but I hate the **** thing. Has anybody else experienced the shifting probs that I have and has anyone tried the Bav Auto free flow valve?
01-04-2008, 06:46 PM
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My Ride: 545iSMGSilver GrayAuburn Dakota LeatherLogic 7 Premium SoundSports Package
I would recommend getting the one from Zackhausen over what BavAuto is selling.
01-05-2008, 08:23 AM
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My Ride: 2008 535i, 6spd mtx, Monaco Blue w/Beige interior. Sport, Preimum, Logic 7/HD/I-Pod/USB, Nav sys, rear sunshade, HUD, PDC, Split seats,
Originally Posted by EBMCS03' post='513863' date='Jan 4 2008, 07:46 PM
I would recommend getting the one from Zackhausen over what BavAuto is selling.
+1 - Dave is great to deal with and if you have any questions he will take the time to walk you through it! I'm going to do the same with my '08 535 soon.
01-05-2008, 03:00 PM
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Originally Posted by EBMCS03' post='513863' date='Jan 4 2008, 10:46 PM
I would recommend getting the one from Zackhausen over what BavAuto is selling.
01-05-2008, 04:30 PM
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Originally Posted by gretamay' post='514104' date='Jan 5 2008, 07:00 PM
I'm not familiar with Zackhausen. Is it Zackhausen.com?
01-05-2008, 06:07 PM
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Originally Posted by iversonm' post='514141' date='Jan 5 2008, 08:30 PM
The spelling is a bit off. Try http://www.zeckhausen.com/.
01-06-2008, 06:46 AM
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I did the Dave Z CDV replacement due to the notchiness of 1st to 2nd shifts. As mentioned previously, I still need to be mindful of clutch engagement during normal driving conditions to get a smooth shift. Under hard acceleration, I do not seem to notice any notchiness.
I would suggest that you think about cahnging out your shifter if you decide to do the CDV replacement. It improves shifting from factory shifter plus a lot of the labor is duplicated on both processes. I have a Rouge SSK and am very happy with it. UUC also makes one.
good luck
al
I would suggest that you think about cahnging out your shifter if you decide to do the CDV replacement. It improves shifting from factory shifter plus a lot of the labor is duplicated on both processes. I have a Rouge SSK and am very happy with it. UUC also makes one.
good luck
al