CDV, in or out?

lightning

Zorg Legend
Joined
Jul 2, 2014
Points
80
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.
 

GazHyde

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M Power
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Dec 2, 2011
Points
226
Location
Berkshire
Model of Z
Z4 MR
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...
 

lightning

Zorg Legend
Joined
Jul 2, 2014
Points
80
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)
 

vintage42

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American Zeds
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Dec 24, 2013
Points
39
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....
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.
 

lightning

Zorg Legend
Joined
Jul 2, 2014
Points
80
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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