Rimozione del Clutch Delay Valve (CDV)

Removing the Clutch Delay Valve (CDV)

Introduction

BMW introduced the Clutch Delay Valve (CDV) to limit the flow of hydraulic fluid to the clutch, aiming to reduce stress on the components. However, this system makes clutch engagement less predictable and sometimes a bit slow, sometimes causing a jerky ride.

I decided to remove the CDV on my 2015 BMW 118i F20 to improve clutch response and gain more direct control.

Required materials

  • 8mm socket wrench
  • Small flat-blade screwdriver
  • 10mm wrench
  • Some hydraulic brake fluid (if needed)
  • A clutch fluid bleeding helper

Procedure

  1. Raise the front of the car with a jack and place it on jack stands (or use car ramps).
  2. Remove the eight transmission cover screws using the 8mm socket wrench. The cover is located under the gear lever. After removing the screws, rotate the cover approximately 45 degrees to fully release it.
  3. Locate the CDV under the car.
  4. The CDV can be removed completely or replaced with a modified free-flow version. I chose to remove it completely. The CDV has a small metal retaining clip, identical to the one on the fluid hose connector.
  5. Once you've located the retaining clips, use the flat-blade screwdriver to pry them up slightly. Next:
    -     Quickly pull the fluid tube off the CDV and cover the end with a finger to prevent excessive leakage.
    - Remove the CDV. Insert the hose directly into the clutch fitting and reinsert the retaining clip to secure it.
    - Alternatively, install a modified CDV before closing everything up again.
  6. Proceed with bleeding the system:
    - Locate the bleed valve.
     - Place a container under the valve.
     - Loosen the valve with the 10mm wrench while a helper presses the clutch pedal all the way down and holds it down.
     - Retighten the bleed valve before the pedal is released.
  7. Reassemble the transmission cover by placing it correctly and retightening the eight screws.

Result

The clutch now responds much more directly to commands, eliminating the delay caused by the CDV. This allows for better control over clutch engagement and a smoother, more precise ride.

If you have a BMW with a CDV and want a more direct feel, this is a modification I highly recommend. In just 20 minutes, you can significantly improve your driving experience.

After work, treat yourself to a beer and enjoy your new clutch feel! 🍻

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