Stvee
Well-Known Member
- Thread starter
- #1
First up, this article covers why you would want to remove your clutch delay valve: https://www.zeckhausen.com/catalog/index.php?cPath=6562
In short, the CDV makes clutch engagement inconsistent and annoying for anyone who is used to driving manual cars. This is especially noticeable on the 1-2 shift with these cars. Removing it just makes the clutch engagement feel like every other car.
In certain use cases it may also help to extend clutch life. For those already experiencing clutch slip, this is not going to be a magic fix.
Tools/materials required:
Small screwdriver
8mm socket
9mm socket
11mm wrench
~2 inch wood screw (make sure the end of the screw isn't slotted like with decking screws, it makes it hard to grip the CDV)
3 feet of 3/16" ID vinyl tubing
1 bottle of BMW DOT 4 brake fluid for bleeding or whatever you normally use
~1 hour of time if you've never done this before
1. After the car is in the air, remove the under tray pictured below by removing 10 8mm bolts
2. After removing this tray, you should see the transmission as pictured below. The CDV will be located to the left. You will want to use a 9mm socket to remove 2 plastic nuts holding the metal shield partially pictured at the very left to gain better access to the CDV.
3. Once this is removed, you will have enough access to remove the hard clutch fluid line from the slave cylinder where the CDV is located. You do not need to remove the 12mm bolt holding the clutch line bracket. There is more than enough room to move that line around without removing the bracket. It might not hurt to slightly loosen it if needed.
Before separating the clutch line from the slave cylinder, use a hose clamp on the soft rubber line at the bottom left below. This will prevent more brake fluid from draining than is necessary. Even with a hose clamp in place, you will still lose some clutch fluid. Have something underneath to catch it.
The CDV location is pointed out in the picture below. Simply use a small screwdriver to pry the clip up enough to separate the hard line from the slave cylinder. The clip does not need to be completely removed. You can see how much I pulled it up in a picture further down.
4. Once the clutch line is separated from the slave cylinder, insert a 2" wood screw into the very center of the slave cylinder opening where the CDV is located and twist until you feel it grip the CDV. Make sure you have a good screw with sharp edges at the tip or you may have issues with this part.
At this point you should just be able to pull the CDV and rubber spacer out with a minimal amount of force. There isn't anything holding it in like other styles of CDV BMW has used in the past.
The culprit removed
5. Now all that is left to do is reattach the hard clutch line to the slave cylinder and bleed the clutch. Attach a 3 foot long piece of 3/16" ID vinyl tubing to the bleed valve for clutch bleeding. This is located on the slave cylinder as well.
I'm not going to cover the specifics of clutch bleeding because it's the same as on any other BMW and there are tons of guides already out there that cover this. I personally used a Motive power bleeder but the old clutch pumping method should be fine as well.
*** I should also mention that instead of removing the CDV itself from the slave cylinder, you can replace the whole slave cylinder with the version from the E90 chassis below. It's the same thing but does not contain the CDV like our cars. It was located in a different position on those.
BMW part# 21526785964 -- costs around $80
In short, the CDV makes clutch engagement inconsistent and annoying for anyone who is used to driving manual cars. This is especially noticeable on the 1-2 shift with these cars. Removing it just makes the clutch engagement feel like every other car.
In certain use cases it may also help to extend clutch life. For those already experiencing clutch slip, this is not going to be a magic fix.
Tools/materials required:
Small screwdriver
8mm socket
9mm socket
11mm wrench
~2 inch wood screw (make sure the end of the screw isn't slotted like with decking screws, it makes it hard to grip the CDV)
3 feet of 3/16" ID vinyl tubing
1 bottle of BMW DOT 4 brake fluid for bleeding or whatever you normally use
~1 hour of time if you've never done this before
1. After the car is in the air, remove the under tray pictured below by removing 10 8mm bolts
2. After removing this tray, you should see the transmission as pictured below. The CDV will be located to the left. You will want to use a 9mm socket to remove 2 plastic nuts holding the metal shield partially pictured at the very left to gain better access to the CDV.
3. Once this is removed, you will have enough access to remove the hard clutch fluid line from the slave cylinder where the CDV is located. You do not need to remove the 12mm bolt holding the clutch line bracket. There is more than enough room to move that line around without removing the bracket. It might not hurt to slightly loosen it if needed.
Before separating the clutch line from the slave cylinder, use a hose clamp on the soft rubber line at the bottom left below. This will prevent more brake fluid from draining than is necessary. Even with a hose clamp in place, you will still lose some clutch fluid. Have something underneath to catch it.
The CDV location is pointed out in the picture below. Simply use a small screwdriver to pry the clip up enough to separate the hard line from the slave cylinder. The clip does not need to be completely removed. You can see how much I pulled it up in a picture further down.
4. Once the clutch line is separated from the slave cylinder, insert a 2" wood screw into the very center of the slave cylinder opening where the CDV is located and twist until you feel it grip the CDV. Make sure you have a good screw with sharp edges at the tip or you may have issues with this part.
At this point you should just be able to pull the CDV and rubber spacer out with a minimal amount of force. There isn't anything holding it in like other styles of CDV BMW has used in the past.
The culprit removed
5. Now all that is left to do is reattach the hard clutch line to the slave cylinder and bleed the clutch. Attach a 3 foot long piece of 3/16" ID vinyl tubing to the bleed valve for clutch bleeding. This is located on the slave cylinder as well.
I'm not going to cover the specifics of clutch bleeding because it's the same as on any other BMW and there are tons of guides already out there that cover this. I personally used a Motive power bleeder but the old clutch pumping method should be fine as well.
*** I should also mention that instead of removing the CDV itself from the slave cylinder, you can replace the whole slave cylinder with the version from the E90 chassis below. It's the same thing but does not contain the CDV like our cars. It was located in a different position on those.
BMW part# 21526785964 -- costs around $80
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