How to Bleed Brake Lines

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You are slowing down to stop at a traffic light only to find your brakes are soft and the pedal is low. These are telltale signs that air has crept into the brakeline. Fixing the problem is a two-man job that requires bleeding your vehicle’s brakes. The result is a stiffer brake pedal and a more reactive braking system. Here are some tips on how to bleed brake lines.

Steps

Getting Ready

1. 1
   Position your car on a flat surface. Cars with automatic transmissions should be in “Park” and those with standard transmissions should be in first gear. The emergency (or parking) brake should be on at all times.
   
   
2. 2
   Take off the hubcaps (if present), loosen the lug nuts and secure the car on jack stands. Remove all four wheels.
   
   
3. 3
   Release the hood and locate the small, somewhat transparent container on the driver’s side of the car. It will be connected to a little metal block situated toward the backside of the engine. This block is referred to as the master cylinder or the brake fluid reservoir.
   
   
4. 4
   Eliminate any old brake fluid still in the cylinder. Pour in enough fresh fluid to maintain the recommended level for your vehicle.

Bleeding the Brakes

1. 1
   Wipe off any dirt from the cylinder cover and unfasten the cap from the bleeder screw. Use a box-end wrench to conceal the screw while covering the screw’s nipple with one end of the clear tubing. Insert the other end into the disposable container before placing it on the caliper body’s drum unit.
   
   
2. 2
   Hold onto the box wrench while firmly clutching the container. Have your “partner” tap the brakes a few times before holding the pedal to the floor until instructed to let go.
   
   
3. 3
   Open up the bleeder screw briefly to allow liquid to flow through the tubing. Fasten the screw securely in place while your partner lets out the brakes.
   
   
4. 4
   Check the waste line for bubbles in the brake fluid. Pour in enough brake fluid to maintain a level somewhere between the lowest and highest line.
   
   
5. 5
   Execute the steps for bleeding brake lines for the other wheels in the following order: left rear, right front and left front.
   
   
6. 6
   Make sure your brakes are not spongy and there aren’t any leaks in the connections.
   
   
7. 7
   Get rid of any surplus brake fluid in a proper and safe manner.

Testing the Brakes

1. 1
   Replace all four wheels and hand-tighten the lug nuts. Lower the vehicle to the ground and tighten the lug nuts. Replace the hub caps if necesary.
   
   
2. 2
   Tap the brake pedal a few times without the motor running until all the slack in the line is removed.
   
   
3. 3
   Go for a test drive to see if the brakes are functioning correctly.

   
   

Tips

• Always keep the brake fluid reservoir full.
• Avoid brake fluid coming in contact with rubber or plastic materials.
• Follow proper safety procedures when jacking up a vehicle.
• Bleed your vehicle’s brake lines every two years.

Warnings

• Brake fluid will melt your car’s paint.
• Dirt particles can contaminate brake fluid and cause brakes to fail.
• Do not release the brake pedal until the bleeder screw is closed.
• Only use the brake fluid that is recommended for your make and model vehicle.

Things You'll Need

• Jack stands
• Suction tool, such as a turkey baster
• Wrench (box)
• Brake fluid
• Clear plastic tubing
• Disposable waste container
• Soft cloth

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