Why does the clutch have air again after bleeding?
3 Answers
The possible reasons for the clutch having air again after bleeding are: 1. Reason one: Poor quality of hydraulic fluid with high water content. 2. Reason two: Air leakage in the clutch slave cylinder. 3. Reason three: Air leakage in the oil circuit or connections. Below is an introduction to related content: 1. Clutch: The clutch functions when the vehicle starts and shifts gears. At this time, there is a speed difference between the primary and secondary shafts of the transmission. The engine's power must be disconnected from the primary shaft before the synchronizer can effectively match the speed of the primary shaft with that of the secondary shaft. 2. Principle: After engaging the gear, the clutch connects the primary shaft to the engine's power again, allowing the power to continue transmitting.
I see this issue of air reappearing after bleeding the clutch is quite common in hydraulic clutch systems. I've dealt with many such cases myself, and the main culprit is usually air leaks in the system. For example, if the sealing rings in the clutch master or slave cylinder have aged, or if the pipe connections are loose, air can sneak in from there. Temperature changes causing the hydraulic fluid to expand and contract can also dissolve and release air, making it feel like the air has returned. To completely bleed the system, you'll need two people—one to pump the pedal and another to slowly release the air—while ensuring the clutch fluid level stays within the proper range and doesn't drop too low. If the problem keeps recurring, check for cracks or wear in the seals and try replacing them. Otherwise, you might experience clutch slippage on the road, a spongy pedal, and difficulty getting the car moving, which is quite dangerous. I recommend not delaying and having a professional mechanic inspect it—they can quickly pinpoint the leak with specialized tools, saving you time and fuel costs from repeated repairs.
Last time, my own car had an issue where the clutch kept getting air in the system even after bleeding. It was quite a hassle to deal with. I think there could be several reasons: first, the air bleeding wasn’t done thoroughly, like the bleed screw not being tightened properly or air remaining in the hydraulic line; second, the clutch hydraulic line might have aged and cracked, allowing air to slowly seep in; third, the hydraulic fluid in the reservoir might have been insufficient or contaminated, leading to bubble formation. I tried re-bleeding it myself—first checking and topping up the fluid level, then loosening the bleed valve to let the air out, but making sure not to release it all at once, doing it gradually instead. In the end, I had to take it to the shop, and the mechanic said the slave cylinder seal was failing and needed replacement. This incident reminded me not to overlook such minor issues, as clutch problems can seriously affect gear shifting and driving safety. Paying attention to the pedal feel during regular driving and sticking to scheduled fluid changes and maintenance can help avoid such troubles.
