Hydraulic Clutch Conversion

The RD clutch, as you will all know, is cable operated

After time, the cable stretchs and if used during winter gets very sticky causing heavy clutch action, sore wrists, until the cable eventually snaps. A hydraulic clutch conversion will overcome all these problems and look pretty trick into the bargain! How do you do it ? Easy ! This shows the conversion we carried out on Caz's RD400.

Shopping list

  • 1 x clutch side hydraulic master cylinder
  • 1 x clutch slave cylinder
  • 1 x length of hydraulic pipe
  • 1 x adaptor plate
  • 1 x clutch pushrod extension

  • The master cylinder can be of any type you desire. The YZF750 remote reservoir one here was chosen to match the remote reservoir brake. Chosing the slave cylinder requires a little more thought. It's hard to state the specifics, but getting one similar to the pics (no idea what it came off!!) should see you right. Don't get one that is too deep. You'll need to get an adaptor plate machined up and a pushrod extension made. These items where done by Martin Newlyn in Brightlinsea for a very reasonable price.

    Putting it together

    The adapter plate is screwed onto the side cover from the rear. The cover has to be modified slightly by grinding away some of the webins to allow the bolts to sit neatly inside. The old worm adapator is not needed and the 2 holes used to screw on the outer cover plate for the adjuster nut need to be opened out to allow a 5mm bolt to pass through. Put the pushrod extender on the end of the push rod, checking that it allows the pushrod to be pushed in fully without fouling the pushrod oil seal. The length of the adjuster may need to be fine tuned once the system is fully assembled. If it is too long, you won't be able to engage the clutch! Fit your master cylinder and slave cylinder and connect together with the hydraulic pipe and bleed away! This is pretty much all there is to it!! It took us about 15 minutes to install this example. The hardest part was bleeding the fluid though the system.