Clutch Master and Slave Cylinders, Checking Function

Clutch Master and Slave Cylinders, Checking Function

Before replacing master or slave cylinder, the corresponding tests must be performed in the event of the following problems.

Noises when Pressing the Clutch:

• First check the over-center spring or the clutch pedal switch for noises.

• If there are noises, remove the over-center spring and repeat the test.

• Replace the affected component.

Clutch Pedal Remains on Floor or Does Not Return to Rest Position after Recoupling (clutch pedal no longer actuated):

• Check whether clutch pedal returns completely to rest position. This frees the bleeder hole in clutch master cylinder.

• Watch out for wedged-in footwell trim panel or mats

• Advise the customer not to leave the clutch pedal pressed.

• It can interfere with the self-bleeding function of the clutch system, because the bleeder hole in the clutch slave cylinder can not perform its function.

• The clutch hydraulics is self-bleeding only if the bleeder hole is unobstructed.

• The bleeder hole is integrated inside the clutch slave cylinder. It is visible from the outside.

Check the Entire Hydraulic System for Leaks.

• First check the brake fluid level in the brake fluid reservoir.

• Visually inspect the clutch master and slave cylinders as well as hose/line assembly with its connecting points for leaks to the outside.

• If you find your leaks, you must replace the affected component.

• Bleed the clutch system. Refer to => [ Clutch System, Bleeding ] Clutch System, Bleeding.

High Pedal Force:

• The clutch pressure plate or clutch plate is mechanically faulty.

Pedal Force:

Single disc SAC clutch:

- approximately 140 N over entire life of clutch.

Two-disc SAC clutch:

- approximately 125 N over entire life of clutch.

Clutch Does Not Disengage or Does Not Disengage Completely:

• If there is air in the hydraulic system, bleed the clutch system - refer to => [ Clutch System, Bleeding ] Clutch System, Bleeding - or check the hydraulic system for external and internal leakage.

• The clutch plate is difficult to move on the splines of the input shaft

• If the needle bearing inside the drive plate (centering bearing for the input shaft) is faulty, replace it.

• Foreign body in the clutch system.

• The clutch pressure plate or clutch plate is mechanically faulty.

• Incorrect components installed or components missing (for example, intermediate plate) during repair work.