2004-2007 Lexus RX330 Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2004-2007 Lexus RX330 uses a foot-pedal parking brake that works a small set of drum shoes hidden inside the hat of each rear disc rotor. Most complaints - a pedal that goes too far down, an SUV that creeps on a hill, a brake that drags or will not release - trace back to those shoes being worn, out of adjustment or rusted, or to a stretched or sticking cable. Lexus specifies 5 to 7 clicks of pedal travel, and the fix almost always starts at the rear wheels, not under the dash.

How the RX330 Parking Brake Works

Lexus describes the RX330 system as a drum-in-disc parking brake. The rear wheels stop on normal disc brakes during driving, but the center (hat) section of each rear rotor is machined into a small drum. Inside it sit two parking brake shoes mounted to the backing plate. When you press the parking brake pedal with your left foot, a cable pulls a lever and cam at the backing plate that spreads the shoes against the inside of that drum.

Because the parking shoes only contact the drum when the pedal is set, they wear very slowly. The flip side is that they sit idle for long stretches, so rust on the drum surface and seized pivots and adjusters are more common than worn-out linings.

To set it, Lexus says to hold the service brake with your right foot and push the parking brake pedal down with your left. To release it, hold the service brake, push the parking pedal again, and let it follow your foot back up. The brake system warning light stays on while the parking brake is applied, and a buzzer sounds if the vehicle goes above about 3 mph with it set.

Common RX330 Parking Brake Problems and Symptoms

A warning light that stays on is worth taking seriously. On this vehicle the same red light covers both the parking brake and low brake fluid, and Lexus warns that continuing to drive with low fluid is dangerous. Check the reservoir before you assume it is only the pedal switch.

The Correct Adjustment Spec and Order

The RX330 owner's manual lists the parking brake adjustment as 5 to 7 clicks when the pedal is pushed with 300 N (67 lbf) of force - a firm push, not a stomp. If yours takes more clicks than that, it needs adjustment. If it takes fewer, the shoes may be set too tight and can drag.

The order matters. Always adjust the shoes first and the cable second. The shoes do not self-adjust from parking brake use, and the gap between shoe and drum grows as the drum surface wears or the rotor is replaced. If you take up that slack by tightening the cable instead, the lever at the backing plate starts partly applied, and you can end up with a brake that drags and a cable at the end of its adjustment range.

1. Safely raise and support the rear of the vehicle and remove the rear wheels. Make sure the parking brake is released.
2. Reinstall a couple of lug nuts to hold the rotor flat against the hub so it turns true.
3. Remove the rubber plug from the adjusting hole in the rotor and rotate the rotor until the hole lines up with the star-wheel adjuster.
4. With a brake adjusting tool or flat screwdriver, turn the star wheel to expand the shoes until the rotor locks.
5. Back the adjuster off by the number of notches given in the factory repair manual, until the rotor turns freely without drag. Trade guidance is clear here: do not estimate - back off exactly what the manufacturer specifies.
6. Reinstall the plug, repeat on the other side, then check pedal travel. Only if it is still outside 5 to 7 clicks should you adjust the cable at the pedal end.

After the shoes are replaced or the drums are resurfaced or replaced, Lexus says the system needs a bedding-down procedure so the new linings seat against the drum. The owner's manual assigns this to the dealer; the exact speed, force and distance are in the factory repair manual. Skipping it is a common reason a freshly rebuilt parking brake still will not hold on a hill.

When the Shoes, Hardware or Cable Need Replacing

Lexus lists a parking brake lining wear limit of 1.0 mm (0.04 in.). Linings at or below that, cracked or separated linings, and linings soaked with grease or axle seal oil should be replaced as a set on both rear wheels. Replace the return springs and hold-down hardware at the same time - they are cheap, they weaken with heat and rust, and a broken spring is what causes most rear scraping noises. Shoes and hardware are in our brake shoes collection and brake hardware kits.

Inspect the drum surface inside the rotor hat too. Heavy rust scale, a lip at the edge or deep scoring means the shoes will never make full contact. Because the drum is part of the rear rotor on the RX330, a badly worn drum surface means replacing the rotor. If you are replacing rear rotors anyway, this is the time to do the parking brake shoes, since the rotor has to come off to reach them. For RX330 owners who want an upgrade, we carry the EBC 3GD slotted rear rotor set for the 2004-2007 RX330, and our full range is in brake rotors.

Cables are the last item. Trade technicians note that cables stretch over time and that the equalizer and pivots can rust and bind. If the shoes are correctly adjusted and the pedal still needs more than 7 clicks, or the pedal feels gritty and does not return fully, the cable is the next suspect. Do not spray lubricant or solvent into the cable housing - it attracts grime and washes contaminants deeper into the sheath.

How Hard Is This Job on an RX330?

Shoe adjustment is an easy driveway job once the wheels are off - most of the time goes into lining the adjusting hole up with the star wheel. Replacing the shoes is moderate. You have to remove the rear caliper and bracket (hang the caliper, do not let it hang by the hose), pull the rotor, which may be rusted to the hub, and then deal with the springs and hold-downs, which reward patience and a drum brake spring tool. Cable replacement is the most involved because the cable runs under the body to the pedal.

While the rear brakes are apart, check pad thickness front and rear against the Lexus pad wear limit of 1.0 mm (0.04 in.), and top up with DOT 3 or SAE J1703 fluid, which is what Lexus specifies. If the fronts are due as well, we carry EBC Yellowstuff front pads for the 2004-2007 RX330 and a wider range in brake pads.

A quick owner check from the Lexus maintenance section: on a safe incline, the vehicle should be held securely with only the parking brake applied, and the pedal should have the proper travel. If it fails that test, it is time to inspect the rear shoes.

Frequently Asked Questions

How many clicks should the RX330 parking brake pedal take?

Lexus specifies 5 to 7 clicks when the pedal is pushed with 300 N (67 lbf) of force. More than that means the shoes or cable need adjustment.

Does the RX330 have a separate parking brake drum?

Not a separate part. It is a drum-in-disc design: the drum is machined into the hat of the rear rotor, and the parking brake shoes sit inside it.

Should I adjust the cable or the shoes?

Adjust the shoes first at each rear wheel. Only adjust the cable if the pedal travel is still out of spec after the shoes are set correctly.

Why does my parking brake not hold after new rotors?

A new rotor drum surface usually leaves a bigger gap to the shoes, and new contact surfaces need bedding-down. Readjust the shoes, then have the bedding-down procedure done as Lexus directs.

Is there a recall on the RX330 parking brake?

NHTSA recall records for the RX330 do not list a parking brake recall. They do list a 2004 brake light switch recall, so check your VIN on nhtsa.gov for open campaigns.

Can I use the parking brake in freezing weather?

Lexus advises against it when the brake could freeze. Put the transmission in Park and block the rear wheels instead.

Sources

1. Lexus RX330 Owner's Manual (Toyota/Lexus publications) - drum-in-disc system, bedding-down, 5-7 click adjustment spec at 300 N, 1.0 mm lining and pad wear limits, DOT 3 fluid, set and release procedure, warning light and buzzer, freezing caution, incline check
2. Brake and Front End: Adjusting Parking Brakes - drum-in-hat construction, star-wheel adjustment, follow the exact back-off spec, cable stretch, rusted equalizers and pivots, no lubricant in cables
3. Wilwood: How to Adjust an Internal Drum Parking Brake - access plug and star-wheel adjustment through the rotor hat, back off until the drum turns freely
4. NHTSA recall records for the Lexus RX330 - no parking brake recall listed; 2004 brake light switch recall