Consider yourself in trouble if your clutch pedal fails to rise back up after you stepped on it. That can only mean that the clutch master cylinder isn't working properly. Once that occurs, its parts won't get the hydraulic fluid they need to operate smoothly. See, the clutch master cylinder is a container that houses the hydraulic fluid that your clutch system uses. Once you step on the clutch pedal, the cylinder releases the fluid through a pipe that's connected to the clutch slave cylinder. This produces hydraulic pressure which is used to make the entire clutch assembly fully operational. Because of what this device does for your vehicle, it's constructed from premium materials to keep it from deteriorating quickly. That means, no matter how often it's used, you're assured that it won't break down at once. It's also designed to match your ride's specifications ensuring a perfect fit during set-up. As a result, you won't be forced to make unnecessary modifications to the cylinder or your vehicle. So before your clutch pedal shows any signs of failing, make sure your ride has got a working clutch master cylinder installed. That way, you won't run into any clutch-related problems while you're on the road, enabling you to get to your destination safe and sound.
Clutch Master Cylinder Buyer's Guide
- The clutch master cylinder controls the clutch slave cylinder that’s commonly installed at the other end of the hydraulic system.
- The clutch is operated by applying a force on the clutch pedal. Depressing the clutch pedal activates a connecting metal pushrod that presses the piston inside the master cylinder.
- Clutch master cylinders are divided into two categories known as the seal-over-port type and the center-feed type.
- There are two kinds of clutch master cylinder designs based on the reservoir fitting: integral and remote reservoir systems.
- A bad clutch master cylinder may compromise your vehicle’s driving dynamics and may result in bigger problems involving the clutch and transmission systems.
- OE replacement clutch master cylinders on CarParts.com could cost you from $10 to $250 depending on the part maker and material used.
The clutch is an essential component found on every vehicle using a manual transmission. This mechanical device engages and disengages power transmission by connecting and disconnecting two rotating shafts. Depending on the make and model of your vehicle, a clutch system could operate either with a cable or a hydraulic master cylinder.
Clutches that use cables to connect the clutch pedal and the clutch mechanism are called mechanical clutches. The ones that use hydraulic pressure, on the other hand, are known as hydraulic clutches. The latter features a master cylinder that converts mechanical energy into hydraulic pressure to operate the clutch mechanism.
What is a clutch master cylinder?
To understand how your car’s clutch mechanism works, you have to first know what a clutch master cylinder is. There are two master cylinders in a car: the brake and clutch master cylinder. Both convert mechanical pressure to hydraulic pressure but are meant for two different components.
A clutch master cylinder is a control device that consists of a piston, springs, and a reservoir. It controls the clutch slave cylinder that’s commonly installed at the other end of the hydraulic system. For your clutch system to work, the master cylinder needs clutch fluid, which is essentially a brake fluid. The clutch master cylinder is mounted directly in front of the clutch pedal. A metal pushrod connects the pedal and the master cylinder’s piston.
How does a clutch master cylinder work?
The clutch is operated by applying a force on the clutch pedal. Pressing on the clutch pedal activates a connecting metal pushrod that presses the piston inside the master cylinder. The piston forces the hydraulic fluid into the fluid line and toward the slave cylinder mounted on the clutch housing. This engages the diaphragm spring that holds the driven plate inside the clutch assembly.
Types of hydraulic clutch master cylinder systems
Clutch master cylinders are divided into two categories known as the seal-over-port type and the center-feed type. To be able to fully understand clutch master cylinders, let’s take a closer look at these two hydraulic systems.
Seal-Over-Port Hydraulic System
The seal-over-port system features a pushrod that pushes and pulls the piston inside the master cylinder. When the piston moves, the seals attached to it move forward. Once the primary seal passes over a small port inside the cylinder, it creates a passageway for the hydraulic fluid to flow to and from the reservoir. Pressurized, a fixed amount of hydraulic fluid flows toward the slave cylinder, which disengages the clutch.
Center-Feed Hydraulic System
The center-feed hydraulic system features small hooks attached at the tip of the piston. When the clutch pedal isn’t depressed, the hooks engage a flange on the valve stem. This holds a rubber seal on the opposite end of the valve stem open to allow fluid to flow to and from the reservoir. When the pedal is depressed, the hooks release the valve stem and rubber seal back to the closed position. The fixed fluid is forced to the slave cylinder as the pedal is further depressed.
There are two kinds of clutch master cylinder designs based on the reservoir fitting: integral and remote reservoir systems. Integral reservoir systems feature a hydraulic fluid tank that’s part of the master cylinder assembly, while remote reservoir systems have the master cylinder separated from the reservoir, which is connected by a rubber hose.
Symptoms of a failing clutch master cylinder
If you’re noticing unusual noises or sensations whenever you use your clutch or when you’re shifting gears, they could be due to a problem with your clutch master cylinder. A bad clutch master cylinder may compromise your vehicle’s driving dynamics and may result in bigger problems involving the clutch and transmission systems. If you suspect a bad clutch master cylinder, be vigilant and watch for these symptoms.
No resistance on the pedal
Ideally, you should feel a bit of force when pressing down the clutch pedal. This is due to the hydraulic fluid’s resistance to compression. Little to no resistance on the clutch pedal could mean that there’s a leak somewhere along the fluid lines or in the clutch master cylinder reservoir. If the hydraulic fluid drops below the recommended level, it wouldn’t be sufficient to engage or disengage the clutch system.
Difficulty when shifting
A clutch pedal that’s difficult to depress may affect gear shifting because the clutch may not be engaged properly. A leak could be causing the issue and checking on your clutch master cylinder is your best bet to address the problem.
Clutch pedal stuck to the floor
A clutch pedal that’s stuck to the floor is a hazard and it’s highly recommended that you don’t drive your car if this is the case. In some cases, the pedal may appear to be resting closer to the floor than it originally used to. When this happens, replace your master cylinder as soon as possible.
Fluid overflows from the reservoir
One way to know your master cylinder’s condition is by popping up the hood for a visual check-up on the reservoir while someone presses the clutch pedal. If the fluid in the reservoir overflows every time the pedal is depressed or released, it means that the master cylinder badly needs a replacement.
Fluid leak on the cylinder
Hydraulic fluid leaks along the fluid lines, on the master cylinder, or on the reservoir would compromise the clutch and gear shifting. Doing a visual examination under the hood would help you determine where the fluid is leaking from.
Keep in mind that as the master cylinder wears out, its ability to maintain hydraulic pressure weakens. Driving in this condition is dangerous. It can ruin your clutch and transmission system, which are both more expensive than replacing your clutch master cylinder.
How much is a clutch master cylinder?
OE clutch master cylinder replacements on CarParts.com could cost you from $10 to $250 depending on the part maker and material used. You could either get them as a solo piece or as part of a kit. To get the part that perfectly fits your vehicle, you may indicate its specific year, make, and model on the filter tab under the search menu. Select from the different categories under the “Shop By” section to further customize your search.
Important Facts You Need to Know About Clutch Master Cylinder
Without a functional transmission system, your vehicle will not be able to make full use out of a high-powered engine. The transmission system is what transfers the engine's power output to the wheels, allowing you to adjust and shift between different speeds. An efficient transmission system lets you quickly switch between gears, anytime and anywhere you want! And if your vehicle uses a hydraulic clutch, each gear change is made possible by the clutch master cylinder. The clutch master cylinder houses a reservoir for hydraulic fluid. When you step on the clutch, a plunger pushes through the master cylinder and forces the hydraulic fluid to the slave cylinder. The increased pressure helps the slave cylinder disengage the clutch. In case you're dissatisfied with your vehicle's stock clutch master cylinder, you can have it replaced with a new one from our catalogs. We offer the lowest prices online, so place your orders today!
• Works as soon as you step on the clutch pedal
• Safely houses hydraulic fluid
• Designed according to OE specifications for easy installation
Troubleshooting a Faulty Clutch Master Cylinder
You'd want to make sure that there's enough fluid coursing the clutch lines, so any time you step on the clutch and pull or push the stick shift, you can switch gears easily. To roll with the punches on the road, you want to be able to slow down or speed up with no trouble at all. Don't let a bad clutch master cylinder stand in the way of smooth handling and transmission.
How will you know if your clutch master cylinder already needs to be fixed? Here are some tips:
- See if there's enough fluid left. Check the reservoir tank of the clutch master cylinder. The fluid level should go between the lower and upper marks on the reservoir tank.
- Take a close look at the clutch master cylinder to spot if there's leak or fluid dripping on its side. A leaky cylinder should be fixed right away.
- Put some pressure on the clutch pedal. If it's too soft, you have to bleed the clutch lines to remove air. Use your vehicle manual as a guide.
- Trace the clutch line that runs from the clutch master cylinder to the slave cylinder. If it's damaged or corroded, fluid won't course through the system easily. It needs replacement.
Replacing a bad clutch master cylinder
Difficulty level: Moderate
What you'll need:
- Socket wrench with socket set
- Tube nut wrench
- Catch pan
Step 1: Find the clutch master cylinder in your vehicle, which may be found on the driver side of the engine block.
Step 2: Put a pan under the cylinder to catch the fluid that may leak, as you work on this clutch part.
Step 3: Use the tube nut wrench to take out the nuts that seal the master cylinder. Turn the wrench nut counterclockwise.
Step 4: To detach the master cylinder, pull out the bolts that lock it to the firewall.
Step 5: Position the new master cylinder right to the mounting holes, so that you can seal this to the firewall with bolts. Then tighten the tube nuts.
Step 6: After adding fluid to the master cylinder reservoir, bleed the system.