During use of the clutch brake, common faults include a heavy clutch pedal, slipping, incomplete disengagement (hard shifting), shuddering, jerking and abnormal noise.
1. Heavy clutch pedal: symptoms, causes, inspection and repair. Symptom: the clutch pedal feels heavy and the foot tires easily, with an obvious difference in pedal force compared with other similar vehicles. Causes: (1) release master cylinder assembly: improper adjustment, pedal too high and no free travel; (2) driven plate (friction disc) assembly: excessive friction disc wear (worn to the rivets); (3) clutch master cylinder, slave cylinder, release fork and release bearing stuck and not moving freely; (4) excessive wear of the flywheel and pressure plate working surfaces (wear over 0.5mm); (5) excessive wear of the release fingers (fingertip arcs worn flat) and release bearing (thrust plane worn into a concave arc).

Repair method:

Step 1: Check whether the clutch pedal is too high and whether the free travel is appropriate, and adjust to normal. If the fault persists, proceed to the next step.

Step 2: Check whether the clutch pedal, master cylinder, slave cylinder, release fork and release bearing are stuck or not moving freely, and whether the pedal returns to normal. If the problem remains, proceed to the next step.

Step 3: Check whether the clutch disc assembly, cover assembly and flywheel are excessively worn, and whether the release fingers and release bearing thrust plane are worn excessively. The friction disc of the disc assembly should not expose its rivets; measure with a caliper - the pressure plate working face wear of the cover assembly should not exceed 0.3mm; measure the flywheel installation depth with a depth gauge - wear should not exceed 0.5mm. The release finger arc face should not be worn flat, and the release bearing thrust plane should not be worn into a concave arc; replace parts that do not meet the requirements. Note: during repair, replace only the single part that does not meet the requirement rather than replacing the whole set. 2. Slipping: symptoms, causes, inspection and repair. Symptom: severe shudder on starting, poor acceleration, weak climbing and high fuel consumption, mainly because the clutch torque transmission is reduced, and in severe cases no torque is transmitted. Causes: 1) the clutch slave cylinder has no free travel, so once the clutch wears slightly, the release mechanism jams the release fingers, leaving no return space, reducing the pressure plate clamping force and causing slip and severe wear. 2) Driving habits: not fully releasing the clutch pedal, excessive half-clutch use, overload operation and steep climbing cause severe clutch wear. Inspection method for slipping: apply the handbrake fully, depress the clutch pedal, start in first gear and then release the clutch pedal; if the engine stalls, the clutch is normal; if not, the clutch is slipping and needs disassembly and inspection. Slipping can be traced from the following: 1) driven plate (steel plate) assembly: oiled friction disc, carbonized or burned friction disc, damaged friction disc, or wear to the rivets. 2) Cover (pressure plate) assembly: damaged diaphragm spring, pressure plate working face worn over 0.3mm, deformation, loose mounting screws, release finger runout over 1mm. 3) Flywheel: working face wear over 0.5mm. 4) Release mechanism: no play in the release fork, no free travel in the clutch pedal, no play in the release bearing. 5) Brake system: improper or too tight adjustment causing hot wheel hubs. Repair method: based on the above five causes, repair slipping in the following order: Step 1: If the slip test confirms no slipping, pay attention to the driving method. Step 2: If slipping is confirmed, first check whether the clutch pedal has free travel meeting the manufacturer’s service manual. Check whether the release fork has free travel (7~8mm); adjust to the required range if not, and proceed to the next step if the fault remains. Step 3: Check and adjust the brake system; proceed if unresolved. Step 4: Remove the transmission, check whether the release bearing and release fork are stuck (replace if so), and check whether the clutch has oil (confirm and fix the oil source if so). Disassemble the clutch and check whether the disc assembly, cover assembly and flywheel wear exceeds the limit (replace if so). Check whether the friction disc is burned: light burns can be sanded with coarse sandpaper and reused; severe burns require replacement. 3. Incomplete disengagement (hard shifting): causes hard shifting, and in severe cases the engine must be stopped to shift. Test method: when the clutch fails to disengage, use the following methods to confirm its release point. For more information, please visit the safety chuck official website.