DIY Clutch Delay Valve (CDV) Removal

[puckshaw]

Well I kept bleeding it over and over but the pedal was still staying on the floor. No air was coming out of the lines. As a last ditch effort I just decided to pump the pedal like 50 times and it came back to life. Everything seems good now. I don’t feel good about it but it’s working fine.

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[puckshaw]

Drove the car for 30 minutes and everything feels great. I’ll still be monitoring it closely and might do another bleed on the next oil change just to make sure there’s definitely not any air in the system. For now though it feels great and engagement does feel way better without the CDV.

 

[Sgtfluffy16]

Drove the car for 30 minutes and everything feels great. I’ll still be monitoring it closely and might do another bleed on the next oil change just to make sure there’s definitely not any air in the system. For now though it feels great and engagement does feel way better without the CDV.

If there is still air in the system. It'll work its way up to the brake fluid reservoir, it'll just take some time. But if there is air in the system you should immediately know it whenever you're driving. Especially since you are cycling the clutch pedal multiple times with the system completely closed the air bubble will work its way to the top. But if it's engaging properly and driving fine then I'm sure you got all the air out

 

[puckshaw]

If there is still air in the system. It'll work its way up to the brake fluid reservoir, it'll just take some time. But if there is air in the system you should immediately know it whenever you're driving. Especially since you are cycling the clutch pedal multiple times with the system completely closed the air bubble will work its way to the top. But if it's engaging properly and driving fine then I'm sure you got all the air out

Well that makes me feel better.

 

[pk8]

Just attempted the CVD delete this afternoon. Everything seemed to be going ok but the Motive 0100 wouldn't keep its pressure before I attempted to bleed. Spent hours trying to figure out where the leak was coming from and second guessing myself putting the rubber spacer that was removed with the CDV back in and out on the master clutch cylinder and messing with the slave clutch cylinder for hours until I realized (I think) the problem was with the Motive power bleeder...

I tried covering the hole at the end of the Motive 0100 cap with my thumb and create an air tight seal and the pressure is still not holding. The plastic at the cannister valve seems to be oddly shaped (as seen in the pic below). If this was the problem (not sure if it is), I find this incredibly annoying as the whole purpose of this product is to detect leaks. I have a new replacement Motive 0100 power pressure and another bottle of DOT4 brake fluid inbound while my clutch pedal is on floor because I leaked so much fluid trying figure out where the leak is coming from.

 

[Sgtfluffy16]

Hopefully you bought your bleeder from FCP Euro. If so then it's covered under their lifetime warranty

 

[pk8]

Hopefully you bought your bleeder from FCP Euro. If so then it's covered under their lifetime warranty

I picked it up from Amazon and have a new one inbound to replace the old defective. No complaints here.

 

[DC5UPRA]

Just attempted the CVD delete this afternoon. Everything seemed to be going ok but the Motive 0100 wouldn't keep its pressure before I attempted to bleed. Spent hours trying to figure out where the leak was coming from and second guessing myself putting the rubber spacer that was removed with the CDV back in and out on the master clutch cylinder and messing with the slave clutch cylinder for hours until I realized (I think) the problem was with the Motive power bleeder...

I tried covering the hole at the end of the Motive 0100 cap with my thumb and create an air tight seal and the pressure is still not holding. The plastic at the cannister valve seems to be oddly shaped (as seen in the pic below). If this was the problem (not sure if it is), I find this incredibly annoying as the whole purpose of this product is to detect leaks. I have a new replacement Motive 0100 power pressure and another bottle of DOT4 brake fluid inbound while my clutch pedal is on floor because I leaked so much fluid trying figure out where the leak is coming from.

Did you try pressurizing the motive bleeder dry before attempting the cdv delete?

 

[tracer bullet]

It's a bit late here but one of the things I do when bleeding brakes is to ensure the Motive pumps up and holds pressure before I start taking the wheels off the car. Something to keep in mind for any future work with a pressure bleeder. It's not a big mistake made here or anything, and I'm lucky to have learned to do that from reading what others have gone through. But it's a suggestion to keep in mind for next time.

 

[spaghettihoes]

I had the same issue with a defective power bleeder. As above pressurizing the system (with no fluid in the container) and letting it sit for 10-15 minutes to ensure there isn't any pressure drop off is a great way to check without wasting fluid.

 

[pk8]

Just an update:

I was finally able to get the job done!
I am not a fan of the Motive pressure pumps although others seem of recommend them. I am not sure if this is a known fact but I had to purchase a separate plumber seal tape to seal the metal valve in the middle of the tube. (Only realized that this was the point of leak because oil ran over it and started to bubble.) Also if you pump past the lid notch, it will pump oil into your motor oil reservoir... There was no instructions sent with my kit, and it took a lot of fiddling here and there to figure things out.

Regarding the CDV delete, it was exactly what I wanted fixed with the shifting. Not afraid of that 2nd gear anymore! The mod feels like it brought the manual experience from a negative to neutral experience... like this fixed something that was wrong with the car rather than improving on something. BMW engineers must have their reasons for the CVD... but I will never understand it, as the CVD shift stutter can dampen the manual driving experience enough to get rid of the car in my opinion. Thanks SupraForum for the extensive resource and info to get this done.

TL;DR - get some sealant tape with the Motive pressure pump. CDV delete is a necessity, not an option.

 

[BMWAF]

CDV delete is a necessity, not an option.

After months of having the CDV deleted, I think it's all a bit of a placebo. The only thing that actually improves the shift experience for me is turning off the automatic rev matching function. Is this improvement facilitated by the CDV delete? Maybe?

Still better than owning an automatic. ?

 

[tracer bullet]

Also if you pump past the lid notch, it will pump oil into your motor oil reservoir...

It's for the brakes themselves. Clutch shares the same fluid.

Get a turkey baster syringe thingy and keep it with the bleeder in the box so you can suck some fluid out if it gets too full after the job if needed. I keep everything in the box to help keep it clean.

 

[tracer bullet]

It's for the brakes themselves. Clutch shares the same fluid.

Get a turkey baster syringe thingy and keep it with the bleeder in the box so you can suck some fluid out if it gets too full after the job if needed. I keep everything in the box to help keep it clean.

After months of having the CDV deleted, I think it's all a bit of a placebo. The only thing that actually improves the shift experience for me is turning off the automatic rev matching function. Is this improvement facilitated by the CDV delete? Maybe?

I love the change, it's the 2nd Bimmer I've done it on. I found things a little too "slippy" going into 2nd, like I'd let off the pedal but it'd take a fraction of a second to finish engaging. CDV removed eliminated it.

 

[pk8]

After months of having the CDV deleted, I think it's all a bit of a placebo. The only thing that actually improves the shift experience for me is turning off the automatic rev matching function. Is this improvement facilitated by the CDV delete? Maybe?

Still better than owning an automatic. ?

Hey BMWAF,
Before any knowlege on what a CDV was, I have had problems with the 1-2 gear shift, and it seems others have had the same problem. I had grown so frustrated with this over the last couple months that I started to question whether I should of just gotten the automatic unlocked ECU supra instead (which was available for cheaper when I bought the manual). After I completed the CDV delete, my problems with the 1-2 shift stutter has completely alleviated. At this point, I don't think it is a placebo and it seems others have the same experience.

On the other hand, I actually read some of your earlier post regarding the auto rev matching while upshifting and experimented with turning it on and off. I thought turning it off did help in the beginning but started to have problems again. I actually don't think the auto rev match solves the 2nd gear stutter and is more a placebo in my head ?.

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