05-09-2010, 10:55 AM
Join Date: Feb 2010
My Ride: 325ci 2001
CDV Delete DIY with pics
I know there are lots of these CDV delete threads around but this is just my experience and me practising making DIY threads
The Clutch Delay Valve (CDV) basically softens up the clutch pedal to remove the harshness of the engines power from the car. If you come off the clutch quickly to apply mucho power, the CDV will slow the clutch slightly to make the application less harsh. I wanted my clutch to kick hard when i lifted the pedal quickly, the rest of the time i am capable of managing it myself without some valve interfering. This DIY may seem long and complicated but honestly it isn't I have just been very thorough to make it really clear for people. Read through it and it should make sense, you're basically pulling two pipes off either side of the CDV and sticking them back together!
This job is VERY simple to do (really it is easy i would rate it 2/10).
You will need:
The car jacked up on stands at the front (and rear if you are of a large build to get under the middle section)
1 x 11mm spanner.
2 x 17mm spanner (please get two, this is important).
C-Clamp or mole grips.
Bottle of DOT4 rated clutch/brake fluid.
1 bleed kit (see my sig for brake bleed DIY for info)
With the car up on stands (please use stands for your own safety and not just the jack) crawl under behind the front wheels. Imagine right between the driver and passenger seat, where the under body covering panels end there is a little open space up the side of the clutch housing. There is only really one line/tube, it comes from the front of the car into a little bracket, after the bracket is a metal pipe that wiggles all over the show and then in to the back of a little cylinder (the clutch slave cylinder). Look at the pic below, it is the only thing that looks anything like this down there so should be really easy to spot it:
Just above this where the metal pipe runs to the small slave cylinder, there is a little metal tube sticking out with a small rubber cap on, this is the bleed nipple and will be needed later.
For now though on with the DIY!
Have a look at this pic, i have added some labels to make what i am about to say even more simple
To the right of bolt number 3 (about 6") you need to clamp the line. Use a C-Clamp or some Mole Grips. Don't go mad, there will be no pressure in this line while you are working on it so just a gentle pinch to stop it flowing out. A slow drip is no problem just don't get it on you!
Put your 17mm spanner on bolt number 2, this is just to hold it in place. Put your 11mm spanner on bolt number 1 and start to unscrew. Please note at this point you will start to get fluid leaking out, this is totally fine. Wear goggles if you feel you can't keep it out of your eyes. If it flows and flows and flows, check the clamp and make sure it's tight. I lost enough to fill a normal glass about 1". Once bolt number 1 is loose you can unscrew it with your fingers keeping bolt number 2 held with the 17mm. Once free gently pull the clamped section (bolt number 2) of the hose away, please note bolt number 1 actually extends INSIDE bolt number 2 so do not bend it as you do this.
Grab your second 17mm spanner and put it on bolt number 3 (you did get 2 of them right...). Holding bolt number 3 in place, unscrew bolt number 2. Once loose use your fingers to unscrew bolt number 2. Once bolt number 2 is out you can stamp on it, burn it or keep it to remind you of your victory! This is the CDV. Look through it and look how restrictive the inside of the thing is, the lines going in are massive then this tiny pin hole inside there...
Basically put bolt number 3 where bolt number 2 was. Poke the little pipe from bolt number 1 back through the bracket and using your fingers at first gently screw bolt number 1 and bolt number 3 back together. Nip them reasonably tight with the spanners but don't go wild. That is it! Your CDV is now removed You just need to quickly bleed the system to remove any air you let in when you opened the pipe up to remove the valve.
Handy to have a helper for 5 minutes here, all they have to do is press a pedal when you say so the better half can even do this! Make sure your brake/clutch fluid reservoir is full to MAX and sit the cap back on top. Pop the rubber cap off the bleed nipple and attach your chosen bleeding kit (see my sig for brake bleeding DIY with loads of info on bleed kits). Open the bleed nipple a half turn. Get your helper to slowly depress the clutch pedal and slowly bring it back up. Please note the use of the word SLOWLY. It should take around 4-5 secs to press it down and then 4-5 to bring it back up. On the first few strokes you should get loads of air bubbles. Once the fluid runs clear and bubble free tighten the nipple, remove your bleed kit and put the rubber cap back on the nipple. If you need to do 5 or 6 strokes check the reservoir fluid level and top it up. Once the job is done always fill the reservoir back to MAX.
Your work here is done! Put the car back on the ground and fire it up, go for a test drive. First time you set off please remember what the job you have just done will mean. I most certainly did NOT staul my car after removing the CDV and bleeding the system. This is also a perfect time to bleed your brakes and swap the fluid for fresh stuff. If you are going to do this check my sig for the brake bleed DIY, the clutch is bled after the brakes if you are planning on doing this.
Here is the CDV (bolt number 2) after i removed it:
I'm going to keep it to remind me of how it used to make the car feel.
Hope this helps you guys, any questions hit me up, happy to help.