What to know about the Clutch Slave Cylinder:
A clutch master cylinder contains a reservoir that keeps the brake fluid. It is linked to the clutch slave cylinder through hoses. When you push the clutch pedal, brake fluid flows from the clutch master cylinder to the slave cylinder, applying the pressure necessary to engage the clutch. It has internal and external seals that can malfunction. If the external seals wear out, the clutch master cylinder will leak brake fluid, reducing the amount of fluid in the car and causing the clutch to malfunction. You may also find leaked brake fluid down by the clutch pedal (inside the car). If the internal seals wear out, the clutch fluid will continue to circulate inside instead of being directed to the slave cylinder. In that case, the clutch pedal will go all the way to the floor when you apply the clutch.
Facts to Note:
Each time the clutch master cylinder is changed, it is recommended to change the slave cylinder (connected to the master cylinder through the hose). When the master cylinder goes bad, it is extremely common for the slave cylinder to follow suit. Note some clutch slave cylinders are installed inside the transmission. To change this type of slave cylinder the transmission has to be detached.
How to Fix:
Examine clutch master cylinder and slave cylinder.
Examine the condition of brake fluid.
Examine the operation of clutch pedal.
Remove and change clutch master cylinder and slave cylinder.
Bleed all air from the master cylinder.
Test drive the vehicle.
Habitually during an oil change, mechanics check the amount of brake fluid. If you feel a change in the way the clutch pedal feels (softer pedals) when stepping on it, you should have a mechanic check the clutch master cylinder and hose. Clutch fluid should be changed every 24,000 miles.
Common symptoms indicating you may need to change the Clutch Slave Cylinder:
Clutch pedals goes all the way to the floor.
Brake fluid leaking around the clutch pedal.
Not able to change gears.