Master cylinder in a hydraulic clutch is sticking

Some manual transmission use a hydraulic clutch linkage to release the clutch disc. The clutch pedal actuates a master cylinder which in turn actuates a slave cylinder that releases the clutch disc. If the master cylinder is sticking, the clutch pedal may not be returning to its starting position, and the clutch disc may not reengage with the flywheel.

Table of Contents

• 1. Symptoms
  • 1.1 Clutch Pedal Does Not Return
  • 1.2 Clutch Does Not Engage Gears When Pedal is Released

Symptoms

Clutch Pedal Does Not Return

The clutch pedal, when release, is force back to its starting position by the normalization of hydraulic pressure in the master cylinder. The fluid pushes the pedal back. If the master cylinder is sticking, it will fight against that pressure and prevent the pedal from fully returning.

Clutch Does Not Engage Gears When Pedal is Released

The clutch pedal operation is the first step in separating the engine from the transmission. On a hydraulic clutch, the master cylinder is driven by the pedal. If the master cylinder is sticking, when the pedal is press and release, the cylinder will remain in the depressed position. It may slowly return, but the clutch will remain disengaged as if the pedal is still being pressed.