How to modify your CDV (Clutch Delay Valve)

[T2FFN]

Z4 Rex, please put a link to the braided hose you purchased

Seems an easier step to just do away with it and fit a braided hose... out of interest, how long would it take to replace the hose? I'd pay an garage to do it, don't really have the access or tools anymore

Thanks

Paul

[Z4 REX]

Here is the link for the supplier. I have had a quick look on their website and I cannot see it there so I would get in touch with them and ask them to supply one. I paid $24 USD + $12 USD Shipping. The part number on the pack is BMWC-170. The description they used is "03-04 BMW Z4 Stainless Steel Clutch Line"
I dont think it would take more than 5min once the car is on the ramps cause all it needs is a clip removing and fitting pulled out one end then unscrew the CDV with hose still attached the other end. After that its just beeding the clutch. So therefore having a good guess no more than 30min. I am going to get mine done like I said next service which is due shortly cause the car will be up on ramps to drain the oil anyway. Once fitted then thats the most positive clutch action you can get cause there is no expansion of hoses or delays from the CDV. From what my mechanic told me he recomends braided hoses to all his customers with M-cars. Just a note here for anyone who hasn't got the special push in fitting but just a normal screw one, try these people as they are the first ones I contacted and the supplied me iwth the screw type fittings but did not have the special one then. They might have now? They are based in Silverstone and they are absoulutly brilliant and helpfull. I would recomend them for brake hoses definetly. The picture is of the hose I got from Bonehead Performance.
http://www.boneheadperformance.com/Merc ... rchant.mvc
http://www.earls.co.uk/index.html

[Tref]

Just had my CDV removed. For anyone contemplating this - DO IT! It makes the gearchange/clutch action so much smoother, even just when pottering around town, you don't need to be thrashing it to notice the difference. I really can't understand why car testers don't comment on the delay when testing new BMWs.

[52 CAL]

I had my car in at Birds BMW last friday to have the CDV removed, but was told that they couldn't just 'remove' it because it needs something to replace it as it cannot simply be removed. I realise that others on here have had theirs taken out with no trouble at all - so was wondering if this is different for different models? ie pre and post face lift? and 2.5 -3.0?

ps it cost me £60 to be told this information. Not chuffed

[srhutch]

I had my car in at Birds BMW last friday to have the CDV removed, but was told that they couldn't just 'remove' it because it needs something to replace it as it cannot simply be removed. I realise that others on here have had theirs taken out with no trouble at all - so was wondering if this is different for different models? ie pre and post face lift? and 2.5 -3.0?

ps it cost me £60 to be told this information. Not chuffed

The only problem I have heard with this is the connection could be a bit tight as there is 2" or so of section missing, a good reason to fit a modified one.

[Raify]

I've just got back from fitting a modified CDV. First impressions are excellent, a must-do mod.

[dan_i]

Can someone explain what the actual mod is, and what it achieves? Sorry for being a numpty, but i've read it through and i'm struggling to figure out the purpose.

[srhutch]

The CDV (Clutch Delay Valve) mod removed the delay valve so that when you take your foot of the clutch the clutch is released at the rate you determine and not the rate of the valve.

No delay is applied when you put your foot on the clutch but it is when you take your foor off, it is there for people who cannot drive properly and to reduce drivetrain shock, but it will increase clutch wear and make changing gear smoothly very difficult.

It really is one of the best and cheapest mods you can do.

[Spud]

Does this mod apply to SMG models? I realise I don't have a clutch, but I have no idea if there's something doing a similar job in its stead within the SMG system.

And yes, I am mechanically retarded, so please excuse the stupidity of this question. I really do wish I knew the slightest about car mechanics, but I've no idea how to start.

[dan_i]

Sorry for being a spaz but I just wanna check I've got this right...

This part is taken off completely
http://www.z4-forum.com/user_images/srhutch/cdv1.jpg

and the hose is just put back on without it?

Whereabouts is it located?

Thanks again.

[mmm-five]

You can either take that valve off completely and reconnect the pipe directly - although some say it might make the pipe too tight - or you can remove the insert (as shown in the picture you posted) and refit it.

I can't find the instructions for the Z4, but they're similar on most models (although you've got to remove the panels under the engine/gearbox to get to the valve)

These instructions might help - http://www.bmw325i.net/cdv_removal.shtml - although it might take longer to read them than to do the job

[srhutch]

No the CDV isnt removed completely, the CDV is removed from the car, and the internal removed from that then the CDV is re fitted.

[Tref]

No the CDV isnt removed completely, the CDV is removed from the car, and the internal removed from that then the CDV is re fitted.

Yes it can be removed completely. The pipe just screws up without the short length of connector containing the restrictor. People replace with a new 'opened up' valve to keep the original look in case of warranty claims.

[srhutch]

No the CDV isnt removed completely, the CDV is removed from the car, and the internal removed from that then the CDV is re fitted.

Yes it can be removed completely. The pipe just screws up without the short length of connector containing the restrictor. People replace with a new 'opened up' valve to keep the original look in case of warranty claims.

I am aware of that but most like to keep stealth for warrany reasons etc

[flimper]

Has anybody had this done in the South of England? I want to get this done but am a bit wary about giving it to just anybody to do and don't have the ability to do it myself.