How to Replace a Brake Booster on Vehicles

Brake boosters Vehicles the Vehicles don't typically need replacing. However, if you press on the brake pedal and the pedal goes all the way to the floor (and there are no fluid leaks), that's a good indication that your booster has failed. The brake booster on the Vehicles is mounted to the firewall in the engine bay. You'll need to remove the master cylinder to get to it. If you've never done this job before, you'll need to allow yourself Vehicles least an hour to get through it.

Under The Hood:

• How to Replace a Brake Booster on a Volvo S80
• How to Replace the Brake Booster for a Saturn
• How to Replace the Brake Booster in a 1999 GMC Suburban
• How to Replace the Brake Booster on a Ford Explorer

 How to Replace a Brake Booster on a Volvo S80

Remove the positive battery cable and air filter box, then unbolt the automatic brake system, or ABS, pump from the car. Remove the master cylinder from the brake booster.

Inside the vehicle, disconnect the brake pedal from the brake booster.

Remove the brake line and vacuum line from the brake booster. Unbolt the brake booster from the bulkhead and remove it.

Position the new brake booster. Bolt it in place. Install the vacuum line and brake fluid line.

Reinstall the master cylinder, ABS pump, air filter box, and battery cable.

Connect the brake pedal.

Bleed the brakes by having an assistant pump and hold the brake pedal. With the pedal held down, locate the bleeder port on one of the front brake calipers and loosen it. Repeat the process until the brake pedal feels stiff again. Refill the brake fluid during this process as necessary.

 How to Replace the Brake Booster for a Saturn

Booster Removal

You need to first remove the master cylinder from the brake booster. If your Saturn has ABS, remove the hydraulic control unit out from the inner fender panel using your wrench to loosen the nuts and bolts.

Disconnect the vacuum hose that runs from the engine to the check valve on the brake booster. Remove the check valve.

In the car, along the brake pedal arm, find and remove the clip and retaining pin connected to the booster pushrod; you may need your screwdriver.

Within the engine compartment, open the interior ventilation filter access panel and remove the rubber plug at the bottom of the cowl. There, you should be able to reach the booster's top mounting bolt with your wrench. Remove both mounting bolts. If your socket wrench is too big to fit, use normal box wrenches.

Remove the booster from its bracket and away from the engine compartment; be careful not to damage other components in the compartment.

Installation of New Booster

Follow Steps 3 through 5 above in reverse order when installing the new booster. Torque the mounting bolts with your torque wrench to 15 foot-lbs.

Fit the check valve onto the new booster and securely reconnect the vacuum hose. For ABS-equipped Saturns, re-install the hydraulic control unit and tighten its mounting nuts with your wrench.

Bleed the brakes. Take your Saturn for a short drive nearby to test the braking applications.

 How to Replace the Brake Booster in a 1999 GMC Suburban

Open up the hood. Pull off the rubber vacuum tube leading to the vacuum booster on the driver's side of the firewall by hand. Unbolt the brake master cylinder from the brake booster using an open-end wrench. Pull the master cylinder off of the brake booster making sure not to kink the brake lines.

Look under the dash and locate the brake pedal connection to the booster. Remove the pushrod retaining clip using the needle-nose pliers, then pull the brake light switch and the brake booster pushrod off of the pedal.

Unbolt the brake booster from the firewall with the 3/8-inch ratchet, extension, universal joint and sockets. Go under the hood and take the brake booster off of the firewall and discard it.

Put the replacement brake booster onto the firewall. Bolt it in place with the factory hardware and the 3/8-inch ratchet, extension, universal joint and sockets. Reattach the booster to the brake pedal and put the brake light switch and pushrod retaining clip back onto the pedal.

Put the master cylinder back onto the brake booster using an open-end wrench. Push the vacuum line back onto the brake booster with your hands.

 How to Replace the Brake Booster on a Ford Explorer

Mark the brake lines coming into and out of the master cylinder using masking tape and permanent marker.

Orient the tube wrench so that it grabs the end of the nut by first sliding it over the brake line.

Pull the brake lines out of the master cylinder.

Unbolt the two bolts that hold the master cylinder to the brake booster.

Slide the master cylinder off the brake booster.

Remove the bolts that hold the brake booster to the firewall.

Remove the cotter pin from the pin holding the back of the brake pedal to the master cylinder.

Slide the brake booster to brake pedal pin out of the mounting bracket.

Pull the brake booster off the firewall.

Install the new brake booster. Installation is the reverse of removal.