In many states, the parking brake in your vehicle is required to function properly in order to receive it’s state inspection sticker.The Lexus RX-300 uses a drum-in-hat parking brake system, making replacement of the rear brake pads similar to replacing the front brake pads. Adjusting the rear parking brake is a little more difficult than most vehicles, but is similar to adjusting a drum brake system. You can complete this repair project at home, in about an hour, using basic hand tools.
1. Loosen, but do not remove (about 1/2 turn) the lug nuts on the rear wheels, using the lug wrench. Place wheel chocks behind the front wheels and lift the rear wheels off the ground. Place jack stands under the rear sub-frame and lower the floor jack until the vehicle is resting on the jack stands. Remove the rear wheels using the lug wrench, and place the wheels aside so they are not in the way.
2. Work on one brake at a time, so you will always have a complete assembly as a visual guide. Remove the two 14-mm slide pin bolts that attach the caliper to the caliper bracket. Slip the caliper off the bracket and remove the rear brake pads. Do not allow the caliper to hang from the brake line hose. Remove the two 14-mm bolts that secure the caliper bracket to the hub assembly. Remove the bracket and the rotor to gain access to the parking brake shoes located inside the rotor.
3. Inspect the parking brake shoes and replace them if they are worn out. Inspect the drum surface on the inside of the rotor and replace the rotor if the surface is worn or grooved due to metal contact with the worn shoes. Rotate the star wheel adjuster, which is positioned between the upper portion of the shoes, counterclockwise to expand the shoes. They should allow the rotor to just slip onto the hub. If they are to loose, the parking brake lever will not have enough travel to engage them with the drum when the parking brake is applied.
4. Slip the drum into place on the parking brake shoes and hub assembly. Bolt the caliper bracket onto the hub, and assemble the brake pads and caliper onto the bracket. Tighten the 14-mm bolts securely. Install the wheels and lower the car to the ground. Pump the brake pedal a few times before test driving and testing the parking brake.