The hydraulic system that actuates the clutch in your manual-transmission car will not last forever. Just like every wear item, the master and slave cylinders will fail eventually. The slave, located near the gearbox, is usually the first to go. Back in the day a clutch cable was the method used, but newer cars utilize a hydraulic system. For old-school enthusiasts like me, the cable-type is preferred. Still, the hydraulic system has its advantages. It will not fail like a snapped cable. There will be warning signs. Here’s what to look out for.
What you need:
*Clutch master cylinder
*Clutch brake cylinder
*Eye and hand protection
*Rags and water
*If you are handy with a socket wrench and ratchet, this job is quite easy and fun to do.
Set? Here's how to go about the process:
What is the color of the clutch fluid in the master cylinder reservoir? If it is dark and mucky, that’s a sign that it will fail very soon. Now, locate the clutch slave cylinder. This is usually positioned on the bell housing of the gearbox, near the clutch disc, pressure plate, and release bearing.
Undo the clutch slave first. Be delicate with the metal clutch line and fittings. You don’t want to damage any of the lines. Be prepared to catch any clutch fluid using a bottle of some sort. The fluid is filthy and black. Next, remove the clutch master.
Flush the clutch line by pumping clean brake fluid into it. Use a clean oil can and a flexible hose. Now, install the master and slave cylinder but do not over tighten the fittings. Fill the reservoir with new brake fluid.
Bleed the clutch system. Ask a companion to pump the clutch pedal repeatedly, and then hold it down firmly in place. With the pedal down, open the bleed screw to let any air out. You will hear it. Repeat the pumping (bomba) and hold (pirme) the cycle until all air is out of the system and the clutch pedal feel returns.
Important things to check:
*Clutch hydraulics will not fail without warning. If you find it harder to shift into gear, and if the clutch pedal feels mushy, it is time to take a closer look at the system. Worn grooves in the cylinder cause the loss in pressure.
*Do not mistake this for a slipping or worn-out clutch disc. That’s a completely different job.
*You can buy a clutch repair kit, but changing the whole assembly is a better idea.
*Brake fluid is highly corrosive and can destroy paint. Work with care. Rinse off with water immediately if it gets on any painted panels.
*To increase the longevity of hydraulic parts, change the fluid once a year or when you notice discoloration.
Note: This article originally appeared in Top Gear Philippines' December 2016 issue.