Simple Tips On How To Bleed A Clutch With A Vacuum Pump

Simple Tips On How To Bleed A Clutch With A Vacuum Pump

The term “clutch” refers to a system that connects or disconnects the engine from the rest of the transmission components. You’ll find the clutch situated between the engine and the transmission. The clutch disengages from the system during activities like starting, changing gears, and even stopping and idling.

Bleeding the clutch is a procedure that involves draining all fluid from the system and refilling it with pure liquid. Bleeding a clutch eases stiffness in shifting gears in a  car. One way to bleed a  clutch is by using a vacuum pump. How can you get this done? Read to learn more!

How To Bleed A Clutch Using Vacuum Pump

An adjustable vacuum pump can make bleeding a clutch a lot easier and faster. The entire kit comprises generic components. A vacuum bleeder connects to the bleeder valve on the slave cylinder and draws the fluid from the clutch master cylinder. After that, it draws both liquid and air into a separate vessel.

The procedure is relatively simple. Here’s how it’s done:

  1. First, open the bleeder valve to the slave cylinder with a line wrench.
  2. Attach the vacuum pump to the slave cylinder if you don’t have a companion to help you or prefer to use a hand-operated vacuum pump.
  3. Remove air bubbles from the slave cylinder by opening the bleeder valve and sucking the air bubbles using the vacuum pump. While you’re doing this, remember to keep an eye on the fluid level.
  4. Close the bleeder valve when you detect a continuous trickle of braking fluid without air bubbles.
  5. Start the car and test the clutch for proper performance once the slave cylinder has been bled.

What’s In  A Clutch Bleeder Kit?

When you are ready to bleed your clutch, you’ll  have to acquire some tools:

  • A pressure bleeder,
  • Flexible hose or tubing that fits tightly on the bleeder valve (clear tube is best),
  • Cup or can for storing the liquid
  • Jack and a jack stand
  • A wrench that can fit with the bleed valve (these can be small)
  • Vacuum Bleeder

Why Would You Want To Bleed A Clutch?

 If your clutch isn’t working correctly, you should bleed it. Your clutch may be difficult to release at times. If you try to shift while the clutch is engaged, the clutch may be stiff and remain in gear. When this happens, you need to bleed your clutch. It’s most likely due to air in the clutch system.

What are the other methods of clutch bleeding, apart from the vacuum bleeding method?

Ways To Bleed A Clutch Without A Vacuum Pump

Other clutch bleeding methods do not require a vacuum pump. These include the manual way and the pressure method.

Manual clutch bleeding:

This method involves two persons. One person will pump the clutch pedal while the other person will open and close the valve. Here’s the process:

  • Your partner should depress the clutch pedal as far as they can with the bleeder valve closed. 
  • While your partner keeps pressure on the clutch pedal, open the bleeder valve and let the fluid drain until it slows down. 
  • Close the bleeder valve when the fluid flow slows, and your friend still puts pressure on the clutch pedal. 
  • Return the clutch pedal to its original position and repeat the process. 
  • Continue until no more air bubbles are coming out of the bleeder valve. Because it is easier to compress air than to release the clutch springs, your friend should feel the pedal “stiffen up” as you complete this process.
  • Ensure you lock the bleeder valve tightly after this process.

The pressure method: 

In this process, you connect the clutch master cylinder to a pressure bleeder, which pressurizes the hydraulic system. The pressure bleeder pushes hydraulic fluid into the clutch master cylinder by opening and closing the clutch bleed valve on the slave cylinder.

Symptoms Of A Failing Clutch Master

A clutch master cylinder is a component of manual transmission vehicles. It acts as a pump for the hydraulically powered clutch system. 

The clutch master cylinder sends fluid through the system to the clutch slave cylinder. Finally, the clutch pedal depresses, allowing the clutch to disengage.

A defective or failing clutch master cylinder will usually cause a few symptoms. When these symptoms occur, this alerts the driver to a potential problem that needs to be addressed. 

Servicing an automobile is advisable before symptoms appear, as every savvy car owner knows. Some people, on the other hand, will only visit a mechanic if they notice a problem. Some signs tell you it’s time to change your clutch fluid. Some of these symptoms will include, 

Low or filthy clutch fluid:

Low or dirty clutch fluid is usually the first symptom of the problem. Both symptoms typically appear together. 

If you notice that the reservoir fluid levels have dropped, then it means there’s a leak. Conversely, if fluid levels drop due to a leak, the fluid is likely unclean. 

The seals inside the master cylinder might wear down over time and contaminate the fluid, resulting in the dirty liquid. In addition, as time passes, aging seals become more vulnerable to leakage.


The difficulty in shifting gears is the second indicator you may need to change the fluid. The master cylinder is hydraulic, and it is prone to internal leakage. 

Internal leaks will create clutch fluid displacement issues, affecting the overall clutch functionality. If the master cylinder cannot generate sufficient pressure, the clutch will disengage and cause the gears to grind when shifting. Potentially it’ll cause the transmission to pop out of gear.

Abnormal clutch behavior:

The final symptom to be aware of is abnormal clutch pedal activity. If you’ve been driving for a time, you should be familiar with how the pedal feels. You will notice odd pressure in your pedals if there are any issues with the master cylinder. This abnormal behavior necessitates a master cylinder inspection and clutches fluid replacement.

 A leaking cylinder might make the pedal seem mushy or spongy. In the worst-case scenario, it can make the pedal sink to the floor and stay there when depressed.

The clutch master cylinder is a crucial component. Any flaws with it can quickly lead to issues that damage the vehicle’s general drivability.

Effects Of Air In The Clutch Line

The hydraulic fluid may not entirely disengage the clutch if there is air in the system and can lead to two difficulties, both of which can be costly:

  1. When you stop, the clutch friction material is constantly rubbing against the flywheel. This rubbing might cause the friction material to wear out quickly, requiring a clutch replacement sooner than expected.
  2. During shifts, some power travels into the transmission because the clutch does not entirely disengage. This causes the gear transmission wear out.

How Often Should You Change Your Clutch Fluid?

You should not only change the clutch fluid if you have a problem with your clutch gearbox. However, we recommend you change the fluid every two years at the very least. 

If you observe a decline in fluid or dirt in the liquid, you should immediately change it. The only method to identify these changes is to check the clutch fluid regularly. 

Check your clutch fluid every four months to see whether it is unclean or if the volume is decreasing. If you notice a difference, have a mechanic examine it and provide you with competent advice.

How The Clutch Works

Because the engine rotates continually, but the wheels do not, a clutch is essential in a car. A vehicle’s wheels must separate from the car engine in some way if you want to stop the car without killing the vehicle engine. The clutch allows for the smooth engagement of a spinning engine to a non-spinning transmission by regulating slippage between the engine and the vehicle’s transmission. Friction between the clutch plate and the flywheel is what makes a clutch work.

Releasing the clutch pedal in a manual transmission car will cause springs to drive the pressure plate against the clutch disc. The pressure plate then presses against the flywheel. This pressure connects the engine to the transmission’s input shaft, causing both to spin at the same rate.

Clutch Components

A modern clutch comprises four essential parts: the cover plate, the driven plate, the pressure plate, and the release bearing.

The cover plate attaches to the flywheel, and the pressure plate applies pressure on the driven plate through the diaphragm spring. In older cars, the pressure comes from coil springs. 

The driven plate moves on a spinner shaft nestled between the pressure plate and the flywheel. When fully engaged, a material on either side creates friction that grabs the pressure plate and flywheel. When the clutch pedal becomes partially depressed, it can slip to a point where the drive can go smoothly.


Clutch bleeding is a maintenance procedure that involves draining all fluid from the clutch and replacing it with fresh, pure liquid. Bleeding your clutch helps to ease stiffness in your gear. 

One way to bleed your clutch is by using a vacuum pump. This process involves connecting a vacuum bleeder to a bleeder valve and draining the fluid from the clutch master cylinder. 

You’ll find a more detailed description of this process in this article. Other ways to bleed a clutch include a manual method and the use of pressure.


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