Clutch
Clutch Master Cylinder
A clutch master cylinder turns pedal pressure into hydraulic pressure that the slave cylinder uses to release the clutch. We carry 44 clutch master cylinders from $20 to $219 for 1984-2013 vehicles, from brands such as Dorman, Centric and LUK, with fits for the Chevrolet S10, Corvette, Jeep Wrangler and Ford Ranger.
Shop clutch master cylinder by vehicle
Symptoms of a failing master
Watch for a clutch pedal that feels soft or spongy, sinks slowly to the floor, or stays down after you press it. Gears may grind or become hard to engage because the clutch does not fully release. Fluid on the firewall under the dash, wet carpet near the pedal, or a reservoir that keeps dropping all point to a leak. Internal seal wear can cause the pedal to fade without any visible fluid loss.
Master alone or a matched set
Some listings are the master cylinder only, with the reservoir included. Others are a complete master and slave cylinder assembly that comes as one connected unit. On vehicles where the slave sits inside the bell housing, a pre-assembled set can save time, but check the listing for whether the line is pre-filled and bled. If the master cylinder failed from age, the slave is often near the end of its life too. Match the line fitting and mounting pattern to your old part.
Bleeding and fluid
Use the fluid type shown on your reservoir cap or in the owner's manual, and keep it off painted surfaces. After installing a separate master cylinder, bleed the system until the pedal is firm and no air comes from the bleeder. Some vehicles are hard to bleed and need a pressure or reverse bleeder. Select your year, make and model, and check the fitment table for engine and transmission before you order.
Clutch Master Cylinder questions
How do I tell if it is the clutch master or slave cylinder?
Look for leaks first. Fluid at the firewall or inside the cab points to the master. Fluid at the bell housing or slave points to the slave. If there is no visible leak and the pedal sinks, internal master seals are a common cause.
Do I need to bleed the clutch after replacing the master cylinder?
Yes, unless you installed a pre-filled, pre-bled assembly that stays sealed. Any air in the line will make the pedal soft and stop the clutch from releasing fully.
What fluid goes in a clutch master cylinder?
Most share the brake fluid reservoir type, usually DOT 3 or DOT 4, but always check the cap or your owner's manual. Do not mix in power steering or transmission fluid, which can damage the seals.