How to Bleed a Slave Cylinder
The clutch slave cylinder in your car works much the same way a clutch cable does in other cars. It is used to engage the clutch release mechanism when your vehicle shifts gears. If you ever need to replace the slave cylinder, or if it is creating too much pressure, you will need to bleed the cylinder. You can bleed the cylinder to reduce pressure in the clutch pedal or to drain old or contaminated brake fluid in the cylinder. Bleeding a clutch slave cylinder is a very easy DIY task, and this easy to follow step by step guide will show you how to it.
Step 1 - Prepare the Vehicle
Park the vehicle on flat, level ground. Then, disconnect the negative battery cable from the terminal post on your car battery.
Step 2 - Raise and Secure the Vehicle
Raise the vehicle using the floor jack, and then place the vehicle on jack stands.
Step 3 - Remove the Hydraulic Line
Place the plastic drip pan underneath the slave cylinder. Next, apply some penetrating spray to the nut that is used to secure the hydraulic line to the slave cylinder. After the penetrating spray has set in for a couple of minutes, use a wrench to remove the hydraulic line from the slave cylinder. When removing the line, be careful not to bend it too much as it may break.
Step 4 - Drain the Clutch Slave Cylinder
Allow brake fluid in the slave cylinder to drain into the drip pan.
Step 5 - Fill the Slave Cylinder with Brake Fluid
Reconnect the hydraulic line to the slave cylinder. Then, remove the fill plug cap fill the cylinder with brake fluid until it reaches the fill line level.
Step 6 - Perform Initial Bleed
Use a screwdriver or a wrench to loosen the slave cylinder bleeder valve. Do not open it completely, but rather, turn it only until fluid starts to leak out and you hear air escape from the cylinder. Then, close the bleeder valve.
Step 7 - Refill the Slave Cylinder
Refill the slave cylinder with fluid to replace any fluid that escaped during the initial bleed.
Step 8 - Repeat Cylinder Bleeding Process
Remove the valve again and bleed the cylinder. However, this time, have your assistant push down on the clutch pedal until it reaches the floor and ask him/her to hold it there. While the panel is pressed to the floor, close the bleeder valve. Then, instruct your assistant to pump the pedal a few times and then release it.
Step 9 - Top-Off Cylinder with Fluid
Once again, fill the slave cylinder with brake fluid.
Step 10 - Final Bleed
Open the bleeder valve again, and have your assistant again push the clutch pedal all the way to the floor and hold it. However, have the helper hold the pedal only, rather than pump it. Close the valve while the pedal is on the floor.
Step 11 - Final Fluid Top-Off
Top-off the slave cylinder for the final time.
Step 12 - Finishing Up
Lower the vehicle, reconnect the negative battery cable and take your car for a test drive to ensure the clutch works properly.