How to Change Hydraulic Clutch Oil in a Motorcycle

A motorcycle's hydraulic clutch operates in a similar manner as its hydraulic brake system, transmitting the energy created from pulling in the clutch lever through pressurized fluid to actuate the clutch mechanism. This fluid, just like in the brake system, can degrade and absorb water over time, reducing the fluid's effectiveness. Left unchecked, the contaminated fluid will damage the clutch master cylinder and render the whole system inoperable. Changing the fluid regularly is a relatively simple task that will ensure that your motorcycle remains roadworthy.

Things You'll Need

• Clear plastic tubing
• Catch container
• 10 mm wrench
• Brake fluid
• Shop rags

Instructions

1. Locate the bleeder screw on the clutch slave cylinder on the motor. The bleeder screw will have a small rubber cap over the bleed nipple. Pull the cap off of the bleeder screw and slip a length of clear plastic tubing over the nipple. Place the opposite end of the tubing into a container to catch the draining fluid.

2. Unscrew the cap from the clutch master cylinder's fluid reservoir on the left handlebar. Carefully pull the inner diaphragm out of the reservoir and set it aside. Top the reservoir off with fresh brake fluid.

3. Unscrew the clutch slave cylinder's bleeder screw a quarter of a turn with a 10 mm wrench. Pull the clutch lever in completely and hold it in place. A small amount of fluid should be expelled from the clutch slave cylinder into the plastic tubing. Tighten the bleeder screw with the 10 mm wrench. Release the clutch lever.

4. Repeat Step 3, as necessary, until the fluid in the tubing turns clear and does not have any air bubbles trapped in it. Check the clutch master cylinder's reservoir often, topping the fluid off, as necessary, to prevent air bubbles from forming.

5. Tighten the bleeder screw with a 10 mm wrench once the fluid is clear and free of air bubbles. Pull the tubing off of the bleeder nipple and wipe it clean with a rag or towel. Push the rubber cap into place over the bleeder nipple.

6. Top off the clutch master cylinder's reservoir. Gently tap the sides of the reservoir and master cylinder to dislodge any air bubbles within the assembly. Wipe the reservoir's diaphragm clean with a rag or towel and insert it into the reservoir. Replace the reservoir's cap.

Tips & Warnings

• Dispose of used clutch and brake fluid responsibly. Take it to your local auto parts store to have it recycled.

• Brake fluid is caustic and will damage painted surfaces. Wipe away any spilled fluid immediately with a rag or towel.

• Only use brake fluid approved for use with your motorcycle. Refer to your owner's manual or contact the manufacturer for specific fluid requirements.

References

• "The Professional Motorcycle Repair Program;" Professional Career Development Institute; 1995