Hydraulic Clutch Diagnosis Diagnostics of a hydraulic clutch system should begin with an inspection of the fluid. Check the fluid and reservoir for dirt and contamination. Foreign matter in the fluid will destroy the seals and wear in grooves in the master and slave’ bores. A soft clutch pedal. Excessive pedal, or a clutch that fails to release when the pedal is depressed can be caused by low fluid in the reservoir. To correct this problem, refill the reservoir to the correct level thin bleed the system. This problem can also be caused by a faulty or damaged primary or secondary seal in the master cylinder. A leaking secondary seal will be evident by external leaks, whereas a primary seal leak will be internal. To correct either of these problems. Replace or rebuild the master cylinder should be replaced and the system. A leaking slave fluid and then bled. If there is an extremely hard pedal, check the pedal mechanism and release fork for binding. If there is evidence of binding. Repair and lubricate the assembly to ensure free movement. A hard pedal can also be caused by a blocked compensation port in the master cylinder. The port may be blocked by improper pushrod adjustments or because the piston is binding in the master cylinder bore. If the piston is binding, the master cylinder should be replaced or rebuilt and the hydraulic system flushed, refilled, and bled. The problem may be also caused by swollen cup seal or contamination in the master or slave cylinders. If this is the problem, the master or slave cylinder should be replaced and the system flushed, refilled, and bled. Restricted hydraulic lines can also cause a hard pedal. The restricted lines should be replaced and the system flushed to remove the debris that may have caused the restriction. A worn clutch disc and/or pressure plate may also cause this problem. If the clutch fails to engage when the clutch pedal is released, check the pedal and release assemblies for binding or improper adjustment and repair them as needed. A swollen primary cup or restricted hydraulic lines can also cause a lack of engagement. Replace the defective parts, then flush and refill the system.