CDV Clutch delay valve location

ZedsDeadbabyZedzdead · Post by **ZedsDeadbabyZedzdead** » Mon Sep 06, 2021 9:31 pm

Evening
Can anyone please confirm the location of the CDV on a Z4c manual, seem some videos online that appear to be underneath a car however I’ve seen someone selling them saying it’s located under the pedal and it’s a 15 second job?
Thanks

Zedebee · Post by **Zedebee** » Mon Sep 06, 2021 9:49 pm

I’d need to get under the car to confirm exact location, but it’s definitely not under the pedal. It’s on the passenger side about half way back. It’s not a big job, but it’s not 15s either. You may need to bleed the clutch (again not too difficult), depending on how much fluid you lose.

ZedsDeadbabyZedzdead · Post by **ZedsDeadbabyZedzdead** » Mon Sep 06, 2021 9:50 pm

Thanks for confirming, it doesn’t sound like something an untrained person like me can do

Mr Tidy · Post by **Mr Tidy** » Mon Sep 06, 2021 9:57 pm

It's underneath the car and in between the clutch slave cylinder and the end of the hydraulic pipe.

I believe you just need to unscrew both ends and put the pipe straight into the slave cylinder, but you don't want to let any air in. That's why mine was done by my Indy during a service!

Ross at RBM charged £32.50 + VAT to remove it and bleed the system - so half an hour labour. Definitely money well spent.

inkey$ · Post by **inkey$** » Tue Sep 07, 2021 8:24 am

The other thing you mention is the clutch pedal stop thats found under the pedal. A few people on here (me included) have increased the size of this to reduce needless pedal travel.

enuff_zed · Post by **enuff_zed** » Tue Sep 07, 2021 8:27 am

Mr Tidy wrote: ↑Mon Sep 06, 2021 9:57 pm It's underneath the car and in between the clutch slave cylinder and the end of the hydraulic pipe.

I believe you just need to unscrew both ends and put the pipe straight into the slave cylinder, but you don't want to let any air in.

Any idea how easy it is to bleed if air does get in? As you say, the cost is not high, but I much prefer the satisfaction of doing stuff myself if I can. (Though if Ross was closer I think I'd be a little bit lazier

)

Zedebee · Post by **Zedebee** » Tue Sep 07, 2021 12:32 pm

Link to RealOEM and picture of CDV attached. Under the car to passenger side of gearbox.

https://www.realoem.com/bmw/enUS/showpa ... 1526755892

The CDV has a male thread at one end and a female at the other. It’s just a matter of unscrewing the connectors at either end of the CDV and mating them directly together.

If you put clingfilm under the fluid reservoir cap, you’ll not lose much fluid. Some posts have suggested clamping the pipes as well. Bleeding the system is not difficult (apparently, I’ve never done it), but it’s a two person job; someone to depress the clutch pedal, while the other opens the slave cylinder bleed nipple.

Edit: Ross charged me an hour to remove the CDV and bleed, but I think this included a complete bleed of the hydraulic system as he also changed the brake fluid.

enuff_zed · Post by **enuff_zed** » Tue Sep 07, 2021 12:33 pm

Zedebee wrote: ↑Tue Sep 07, 2021 12:32 pm If you put clingfilm under the fluid reservoir cap, you’ll not lose much fluid. Some posts have suggested clamping the pipes as well. Bleeding the system is not difficult (apparently, I’ve never done it), but it’s a two person job; someone to depress the clutch pedal, while the other opens the slave cylinder bleed nipple.

Thank you.

LBN · Post by **LBN** » Wed Sep 15, 2021 4:12 pm

What are the benefits of removing the CDV? As in, how does the shift feel after?

I'm toying with the idea of removing but I don't know if it's worth the effort.

Zedebee · Post by **Zedebee** » Wed Sep 15, 2021 8:12 pm

Difficult to explain really. Some members have been underwhelmed, some thought it made a big difference. I have found it makes disengagement/engagement more direct which means you can change gear faster without kangarooing down the road, particularly in 1-2 and 2-3.

It’s a pretty simple job whether you do it yourself or get someone else to do it, and it’s completely reversible, so why not?

LBN · Post by **LBN** » Wed Sep 15, 2021 8:40 pm

I have had a bit of kangarooing, I just thought it was me! If it's reversible it's probably worth trying at least.

Post by **srhutch** » Wed Sep 15, 2021 9:19 pm

LBN wrote: ↑Wed Sep 15, 2021 8:40 pm I have had a bit of kangarooing, I just thought it was me! If it's reversible it's probably worth trying at least.

Nobody have ever put it back. That I’m aware of. Believe me you will notice a difference. It was fitted for our yank friends who can’t drive manual cars.

BumpyZ4 · Post by **BumpyZ4** » Wed Sep 15, 2021 9:26 pm

LBN wrote: ↑Wed Sep 15, 2021 8:40 pm I have had a bit of kangarooing, I just thought it was me! If it's reversible it's probably worth trying at least.

I removed mine and there was a definite improvement in shifting and it only took about 15 minutes to remove!

awhc · Post by **awhc** » Sun Sep 19, 2021 1:45 pm

Removed mine the day I got the Z4. Also put in a M10 bolt with a rubber door stop to shorten the clutch throw.

agazetas · Post by **agazetas** » Fri Sep 24, 2021 4:52 pm

Hi everyone, my first post on here!

After reading all of your comments, I am keen to remove the CDV on my E85 2.5i - however, I am a mechanical novice!

Is there anybody out there who would be willing to carry out this work for me (paid)? I have tried to call a few local garages, but they don't seem to want to touch it. I am based in Gloucestershire (Tewkesbury way).

Any help would be most appreciated, and apologies for bringing up an old post again - nothing worse on forums!

Alex

Z4-forum.com

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