Lexus IS300 parking brake shoe, just like other parking brake shoe of other vehicles, is built on a separate mechanism so that it still works even if the main brake fails. If used only when parking, this often does not need replacement or repair and can last for the life of the vehicle. However, due to misuse, natural wear, corrosion, and manufacturing defect, a parking brake shoe may fail. And if it does, you may need to perform troubleshooting.
If your parking brake shoe no longer works, you might need to replace it with a new one. To install a new parking brake shoe in your Lexus IS300, park your car on a level ground. Do not engage the parking brake. Place the vehicle's transmission in reverse or first gear if manual, and in the park if automatic. Remove the tires of the rear wheels. Loosen the bolts of the brake calipers and swing the calipers up. Remove the brake rotor. Now you will be able to see the parking brake mechanism. Unhook the springs using pliers. Remove the pins or clips and then release the parking brake cable. Pull the brake shoes off the plate. Clean all the parts thoroughly and remove the rust with cleaning fluid. Use a rag to wipe the rust and dirt off. Use wire brush if necessary. Apply brake grease on backing plate and pivot joints. Install the new parking brake shoes following the steps in reverse order. Replace other components, such as the springs and pins are heavily corroded. Test the brakes before using the vehicle normally.
If your existing parking brake shoe does not work properly, a simple adjustment may be required. Follow the steps above until you have removed the brake rotor. Locate the shoe adjuster. (This is the part that links both ends of the shoe.) Use a flathead screwdriver and turn the adjuster clockwise to compress the brake shoe and counterclockwise to expand them. Do this on both rear wheels. Check the resistance of the brake shoe by testing the parking brake lever. Return the wheels once you have achieved the right parking brake resistance.
Remove the rotors to expose the parking brake mechanism. Check for corrosion. Use cleaning fluid and rag as described above.