The brake booster located on a 1995 Toyota 4Runner adds additional braking force to the brake master cylinder, making it easier for the operator of the SUV to push the brake pedal. But if the booster fails, it's not a serviceable unit, meaning that it has to be replaced with a new one. Otherwise, the brakes will become difficult to operate. To fix the problem, the booster needs to be replaced, which takes about two hours to do.
Pop the hood on the 4Runner. Unbolt the master cylinder located on the front of the brake booster on the driver's side firewall, using an open-end wrench. Pull the master cylinder off of the firewall, then let it rest on the fenderwell or stay up by the brake lines. Unplug the vacuum line from the brake booster with your hands.
Look under the dash and find the brake booster rod connection to the brake pedal. Take out the clip holding the clevis in the brake booster rod with your hands. Pull out the clevis and pull the rod off of the pedal. Unbolt the brake booster from the firewall from the inside of the 4Runner with the 3/8-inch ratchet and socket.
Pull the brake booster away from the firewall, and peel off the gasket from the firewall with your hands. Install the replacement gasket onto the replacement brake booster, then push it into the firewall.
Bolt the replacement brake booster to the firewall with the 3/8-inch ratchet and socket. Install the clevis and clip into the brake pedal and brake booster linkage to connect the two together. Push the vacuum line onto the brake booster, then bolt the master cylinder to the booster with an open-end wrench.
