[specialist]

I have a 335i 2007 couple

Do i need any parts to do this mod? or do i just remove part and reattach it?

[335NJ]

Originally Posted by specialist

I have a 335i 2007 couple

Do i need any parts to do this mod? or do i just remove part and reattach it?

Just buy the M3 CDV from ECS or a vendor here, and install it in place of the original one. Be cautious to not introduce any air into the system.
https://www.ecstuning.com/BMW-E90-33...aulic/ES41456/

[Nitrousbird]

Don't waste your money/time buying a "high flow" unit. Remove CDV valve and attach the hoses together. Make sure to bleed the clutch afterwords. I recommend doing your brake fluid flush while doing this as it is probably due to be changed anyway.

[Mike@N54Tuning.com]

Originally Posted by specialist

I have a 335i 2007 couple

Do i need any parts to do this mod? or do i just remove part and reattach it?

BMS has a very inexpensive hollowed out OEM CDV.

Mike

[BlackBB6]

Originally Posted by Nitrousbird

Don't waste your money/time buying a "high flow" unit. Remove CDV valve and attach the hoses together. Make sure to bleed the clutch afterwords. I recommend doing your brake fluid flush while doing this as it is probably due to be changed anyway.

This is the way to go.

[specialist]

looking at this pic they just remove the cdv

[MiniXP]

Originally Posted by Nitrousbird

Don't waste your money/time buying a "high flow" unit. Remove CDV valve and attach the hoses together. Make sure to bleed the clutch afterwords. I recommend doing your brake fluid flush while doing this as it is probably due to be changed anyway.

+1. No need to buy a hollowed one. the line didn't seem at all stressed to connect when I did mine.

I did bleed my clutch when I did it, but I was bleeding my brakes anyways. Some people don't bleed, but it is not a bad idea to do it.

[specialist]

I will bleed i will just remove it.

[Jozy]

What's the difference between having a cdv and not? I mean is it really necessary?

[specialist]

This is what i found......



The Clutch Delay Valve (CDV) restricts the flow of hydraulic fluid in the line that operates the clutch when you press the pedal. BMW added this to most or all of its manual transmission cars over the last five to ten years. As I understand it, the purpose is to protect the differential from abrupt power delivery such as dumping the clutch at 5,000 RPM for a drag racing start.

The problem is that the momentary delay makes it hard to feel exactly when the clutch disengages as you release the pedal. It's more of a problem at relaxed speeds / low revs when you're simply trying to drive smoothly. If you're driving more aggressively - say upshifting quickly at > 4,000 RPM - it's not noticeable.

There are many CDV threads on this site and I'm sure most of the explanations are more accurate and thorough than mine - but I hope this is helpful. It's supposed to be a very easy DIY but you need to know how to bleed the air out of a hydraulic line to complete the job properly. Because the clutch and brakes share a fluid reservoir, the tech at my shop also checked all four brakes for air after he changed the CDV.

You can simply remove the valve and reattach the lines on either end but that's a problem if you are still under warranty and don't want the dealer to know that you've modified the car.