I don't know if a car owner has encountered such a situation when driving: when the engine is running, pressing the clutch pedal makes a "rustling" sound, which increases with the engine speed.
This is because the clutch itself has malfunctioned. Analyze and repair according to the fault symptoms. Firstly, the clutch release bearing was inspected and replaced, and then the small bearing supporting the transmission shaft at the rear of the crankshaft was lubricated with grease. The movement of the bearing needle was checked, and no abnormalities were found. After installing the transmission, the sound did not change. Using auscultation to determine the sound location, it was found that the piston rod of the clutch slave cylinder has a loud sound. Considering the possibility of quality issues with automotive clutch accessories, two brands of release bearings have been continuously replaced, but the effect is still not significant. During the test drive again, it was found that when the clutch pedal was first pressed, the sound disappeared instantly and gradually became louder and louder.
After careful analysis, it was found that when the clutch pedal was first pressed, the front support bearing of the first axle was relatively stationary due to the close speed between the first axle and the flywheel, so the sound was not significant. As the speed of one shaft decreases to a complete standstill, the bearing increases with the engine speed, so the noise becomes louder and louder. After replacing the bearing here, the noise disappears.
When pressing the clutch pedal rapidly, the clutch can be disengaged, but after pressing the clutch pedal for a period of time, the clutch cannot be disengaged. The cause of this fault is the aging and wear of the hydraulic brake master cylinder cup, with longitudinal grooves, and severe wear on the inner wall of the master cylinder. Therefore, when the clutch pedal is urgently pressed, due to the viscosity and fluid inertia of the brake fluid, the amount of brake fluid leaking from the master cylinder cup mouth and groove is less, and the amount and pressure of brake fluid in front of the cup are greater, so the clutch can be disengaged. When slowly stepping on the clutch pedal, the pressure oil in front of the main cylinder wrist will be squeezed back into the vacuum chamber behind the cup along the cup mouth and groove, causing pressure to not be established and the clutch cannot be disengaged. After repairing the car clutch accessories, the fault was truly eliminated.
When encountering problems, one still needs to know how to analyze and eliminate each possibility before finally discovering the true problem. The principle of doing anything is similar, as long as you take it seriously, some not too big problems can generally be solved.