How to Bleed a Brake on a Front Wheel

Anytime a hydraulic brake component on the front braking system of your car is replaced, a bleeding procedure is required. Hydraulics rely on constant pressure from the fluid, and when compromised, these systems allow internal air pockets that will reduce the effectiveness of the system. Brake hoses, calipers or steel brake lines comprise the hydraulic system in front brakes. When one or more of these components require replacement, you will need to bleed the braking system to restore the hydraulic pressure.

Instructions

1

Top off the brake fluid in the master cylinder and replace the cap or cover.

2

Place a catch pan beneath the caliper in the wheel you're going to bleed. This will prevent brake fluid from draining onto the surface area where the vehicle is parked.

3

Remove the rubber protective cap from the bleeder screw on the caliper if applicable.

4

Crack open the bleeder screw using a ratchet and an appropriate sized six-sided socket. Bleeder screws are often exposed to the environment and can easily seize in their position. If necessary, apply heat to the area of the caliper surrounding the screw using a portable propane torch to expand the metal housing of the caliper around the screw. Using a six-sided socket on the bleeder screw will help prevent rounding out the screw.

5

Allow the bleeder to gravity bleed once opened. This may take several minutes until a steady trickle of fluid seeps from the open bleeder screw. Hand tighten the screw using a line wrench or a box-end wrench and allow the screw and caliper to cool down if a torch was used.

6

Have an assistant manually pump the foot brake pedal four to five times and then hold the pedal in the down position. This action purges air through the system. While they're holding down the pedal, install an appropriate sized transparent tube to the bleeder screw and place the other end into an empty jug or bottle.

7

Open the bleeder screw again using a line wrench or box-end wrench. The brake pedal in the vehicle will drop further to the floor until the hydraulics are restored. Close the bleeder screw and have the assistant pump the pedal again until the brake pedal feels firm. The brake fluid purging from the bleeder screw should be absent of air bubbles. If necessary, recheck the master cylinder often and add brake fluid to prevent the cylinder from draining completely.

8

Top off the master cylinder to restore the brake fluid lost during the bleeding procedure. Make sure the assistant is not applying pressure to the brake pedal before removing the master cylinder cap or cover before removing it.