How to Bleed a Subaru Clutch with a Vacuum Pump: A Step-by-Step Guide

If you’re an enthusiast who owns a Subaru with a clutch, you may already be familiar with the importance of maintaining the clutch system. One of the essential tasks to keep the clutch system healthy is to replace the fluid and bleed the clutch regularly. Bleeding the clutch is essential as it removes any air bubbles that may form in the system, which could cause issues such as a soft or spongy pedal feel or difficulty shifting gears. In this article, we will show you how to bleed a Subaru clutch system with a vacuum pump, an efficient and effective way to get the job done.

What You Will Need

Before we get started with the process, let’s first gather the necessary tools and equipment:

  • Vacuum pump
  • Clear plastic hose
  • Wrench or socket set
  • Brake fluid
  • Drip pan
  • Assistant (optional)

Step-by-Step Procedure

  1. The first step is to locate the bleed valve on your Subaru’s slave cylinder. You can find it on the passenger side of the transmission, near the top.

  2. Once located, remove the dust cap from the valve and attach one end of the clear plastic hose onto the valve.

  3. Put the other end of the hose into a container or drip pan that has some brake fluid in it. Make sure that there is enough fluid in the container so that it covers the end of the hose.

  4. Connect the vacuum pump to the other end of the hose attached to the bleed valve. Be sure to follow the manufacturer’s instructions for attaching the vacuum pump.

  5. Slowly pump the vacuum pump until you start to see air bubbles in the clear plastic hose. Keep pumping until you don’t see any more bubbles or until you’ve pumped five or six times.

  6. Once you’ve eliminated as much air as possible, close the bleeder valve on the slave cylinder by turning it clockwise.

  7. Remove the vacuum pump from the hose, and replace the dust cap back on the bleeder valve.

  8. Check the clutch fluid reservoir and top up the fluid level if it’s low.

  9. Repeat the process, starting from step 2, until the fluid runs out of the hose and there are no more air bubbles visible.

  10. Once you’ve finished bleeding the system, you can test the clutch’s performance to see if the issue is fixed. Start the car, and with the clutch depressed, shift into all gears. The gears should engage smoothly, and the clutch pedal should feel firm and responsive.

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Safety Precautions

Before attempting to perform any maintenance or repair on your Subaru, be sure to take the necessary safety precautions. Here are some tips that you should follow:

  • Use safety glasses to protect your eyes from any fluid or debris that may splash around.
  • Make sure the car is parked on a level surface, and the parking brake is engaged.
  • Keep the brake fluid away from your skin and eyes as it is highly corrosive and can cause severe injury.
  • Avoid spilling any brake fluid onto the paint, as it can damage the paint and other finishes.

Troubleshooting Tips

If you notice any issues while bleeding your Subaru clutch system, such as not being able to remove all the air bubbles, here are some troubleshooting tips that you can try:

  • Check the brake fluid reservoir to make sure that it’s full and that there are no leaks or cracks in the reservoir or hoses.
  • Try repositioning the clear plastic hose or the vacuum pump to make sure that they can get a good seal.
  • If the vacuum pump isn’t working correctly, try using a different pump.


Bleeding your Subaru clutch system with a vacuum pump is a straightforward process that you can do yourself with the right tools and instructions. The benefits of using a vacuum pump over other methods are that it’s quick, efficient, and can remove more air bubbles from the system. Remember to take the necessary safety precautions and follow the steps to ensure the proper functioning of your car’s clutch system.

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Peter Banks

With years of experience as a professional mechanic and Subaru specialist, Peter is one of the most respected members of our team. He's written several articles on Subaru maintenance and repair, and his advice and tips are always practical and helpful. When he's not working on cars, he enjoys cooking and trying out new recipes.

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