clutch slave cylinder
YouTube: Engineered Mojo

Why a Clutch Slave Cylinder Is Important and How to Spot a Bad One


If you drive a car or truck with a manual transmission, then you probably use a slave cylinder every day. This lesser-known part can be the real culprit in several transmission issues, so it's a great thing to familiarize yourself with and potentially save yourself a fortune down the road.

The clutch slave cylinder is a crucial part of the clutch system in manual transmission vehicles. It's one of several steps in the process of converting mechanical energy through the cylinders' hydraulic system. We'll cover more details on what exactly a clutch slave cylinder is, how the auto part works, and symptoms of a failing clutch slave cylinder.

What Is a Slave Cylinder?

A clutch slave cylinder is a smaller cylinder connected to a larger master cylinder which are both parts of a larger hydraulic system for engaging the clutch. When you push the clutch pedal, a plunge inside the master cylinder forces hydraulic pressure through to the slave cylinder.


The slave cylinder is mounted on the transmission or in the bell housing and connects to the clutch wrench, which puts pressure on the clutch release bearing and pressure plate. This causes the clutch to disengage allowing for free gear movement.

Signs of a Bad Slave Cylinder

If your clutch feels unresponsive, it might be due to an issue with the hydraulic clutch cylinders. One common issue is a leak in the hydraulic tubes. If this type of leak occurs, you'll notice that your clutch has more give before it kicks in.

Often, these cylinders will leak onto the floor. They are a common cause of visible leakage, so if you see clutch hydraulic fluid on the ground when you leave in the morning, in addition to a "spongy" clutch pedal feel, you are likely having issues with a clutch slave cylinder or clutch master cylinder. You may also notice cloudy brake fluid if your slave cylinder O-rings have begun to deteriorate.


Obviously, low fluid levels and deterioration are a bad thing, so this all means it's probably time for a trip to the repair shop. Of course, if you're more mechanically sound and prefer going the DIY route, you could always try replacing the bad clutch slave cylinder yourself. The above video from Engineered Mojo shows how to particularly put a new clutch slave cylinder in 1992-2000 Honda/Acura models, but there is plenty of additional info out there to help you tackle the project on your own.

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This post was originally published on September 10, 2019.

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