How to Bleed Air From Brakes

If you apply your car brakes and find them spongy and low, chances are air has seeped into your brake line. The best way to correct the problem is to bleed your air brakes. Follow these steps to do it yourself.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Jack stands
• Wrench
• Brake fluid
• Clear plastic tubing
• Disposable waste container
• Rag

Prepare Your Vehicle

1. Gather all your tools before you begin. Remove the hubcaps from the tires and unscrew the lug nuts.

2. Set the vehicle on jack stands. Check that it is stable before dismounting the tires.

3. Mount a lug nut backward on each wheel and secure it against the rotor.

4. Pop the hood and locate the brake fluid reservoir. Add brake fluid until the level surpasses the reservoir's seam. The reservoir should never be empty while you're bleeding air from your brakes.

Bleed Your Brakes

5. Find the bleeder screw at the rear of the caliper body and remove its rubber cap.

6. Cover the bleeder screw with a box-end wrench. Take one end of the plastic tubing and cover the bleeder screw's nipple. Position the other end of the tubing into the waste container and set the container on the drum unit or the caliper body.

7. Grab the bottle firmly with one hand while holding the wrench in the other.

8. Ask a helper to pump the brakes several times and hold the brake pedal down until you tell him to release it. When you do, your helper replies, "Applied."

9. Release brake fluid into the waste line by opening the bleeder screw for several seconds. Close the screw and ask your helper to release the brakes.

10. Examine the brake fluid in the waste line for air bubbles. Continue adding brake fluid to maintain the level above the reservoir's seam line.

11. Repeat the bleeding process for each wheel, moving from right to left rear, and then right to left front. Spray each bleeder screw with brake cleaner and rub dry.

12. Check the brake pedal for firmness and examine bleeder screws and other fittings for leaks. Repair if needed.

13. Properly dispose of any excess fluid.

Test Your Brakes

14. Mount your tires on their rims and return your vehicle to level ground. Tighten the lug nuts and replace the hub caps.

15. Pump the brake pedal several times with the car's motor shut off until all clearances are taken up.

16. Test drive your car to ensure the brakes are working properly.

Tips & Warnings

• Keep brake cleaner from making contact with rubber or plastic parts.
• The brake fluid reservoir should be full at all times.
• Use a proper fitting box wrench to loosen the bleeder screw.
• Don't release the brake pedal if the bleeder screw is open

[tovtov]

on 3/26/2009 03/26/2009- version 5.90.1.1 for new About eHow Add a comment

[cricketgo]

on 3/16/2009 Great instructions. We always just crawled under the vehicle to get to the bleeders instead of raising it and putting it on jack stands. I also found that a deep socket to fit the bleeders works well in case you find one that is too tight due to rust or other reasons.

[poster]

on 11/28/2007 This is great.