1993-2000 Lexus LS400 Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 1993-2000 Lexus LS400 holds itself with a small set of drum brake shoes hidden inside the hat of each rear rotor, applied by a foot pedal and a pair of cables. When the parking brake stops holding on a hill, drags, or takes too many clicks to set, the fix is almost always the same order of work: adjust the shoes at each rear wheel first, then take up any slack at the cable adjuster, and replace the shoes or cable only if adjustment cannot bring it back.

How the LS400 Parking Brake Works

The LS400 uses rear disc brakes for normal stopping, but the parking brake does not use the rear calipers. Instead, the inside of each rear rotor hat is machined as a small drum, and a pair of parking brake shoes sits on the backing plate inside it. This layout is called a drum-in-hat parking brake. Stepping on the parking brake pedal pulls a cable that operates a lever at the bottom of each backing plate, which spreads the shoes out against the drum surface.

The shoes are set by a star-wheel adjusting screw at the top of the backing plate. You reach it through an access hole in the rotor hat that is normally closed with a plug. Because the shoes only touch the drum when the parking brake is applied, they wear very slowly, and many LS400s are still running their original parking shoes.

Lexus changed the parking brake shoes between generations. The 1990-1994 cars (UCF10) and the 1995-2000 cars (UCF20) use different shoe assemblies, with separate left and right parts, so order shoes by model year rather than just "LS400."

Using the Parking Brake Correctly

The owner's manual keeps it simple: fully depress the parking brake pedal to set it, and pull the release lever to let it off. Before you drive, the manual says to confirm the parking brake is fully released and the reminder light on the dash is off. That light is the same brake system warning light used for other brake faults, so if it stays on after the parking brake is fully released, check the brake fluid level next.

The manual's periodic checks also include the parking brake: make sure the pedal has proper travel and that, on a safe incline, the car is held securely with only the parking brake applied. That incline test is the simplest way to tell whether yours needs attention.

Use the parking brake regularly. A drum-in-hat brake that is never applied lets rust build up on the drum surface and the shoes, and the adjuster and lever can seize. Setting it each time you park keeps the parts moving and the friction surfaces clean.

Common LS400 Parking Brake Problems and Symptoms

• Won't hold on a hill: The shoes have worn or been left loose after a rear brake job, the lining is glazed or contaminated, or the cable has stretched. A worn equalizer pivot can give normal pedal travel while the brake still fails to hold.
• Pedal goes down too far: Extra clicks before the brake holds usually means shoe clearance has grown or cable slack has built up. Adjust the shoes first; cable adjustment alone only hides worn shoes.
• Dragging or a hot rear wheel: The shoes are adjusted too tight, a cable is seized in its sheath and not returning, or the release lever is not fully letting go. Drag can also come from a sticking rear caliper, so check which part is causing it before buying parts.
• Scraping or rattling from the rear: A broken hold-down or return spring, or lining separated from a shoe, can let parts rattle inside the rotor hat.
• Rear rotor will not come off: Rust inside the drum or shoes set against a worn lip on the drum can trap the rotor during a pad and rotor job.
• Warning light stays on: Confirm the pedal is fully released, then check the fluid level and the parking brake switch.

How to Adjust the LS400 Parking Brake

Adjustment is a two-stage job, and the order matters. The shoes set the baseline clearance; the cable only takes up what is left. If you tighten the cable to make up for loose shoes, the pedal may feel right while the brake still holds poorly.

1. Raise and support the rear on stands, release the parking brake, and remove the rear wheels.
2. Hold the rotor in place by threading on a couple of lug nuts, then remove the adjuster hole plug in the rotor hat.
3. Expand the shoes: Rotate the rotor until the hole lines up with the star wheel. Using a brake adjusting spoon or flat screwdriver, turn the star wheel to expand the shoes until the rotor locks.
4. Back off: Turn the adjuster the other way the number of notches listed in the factory service manual, until the rotor turns freely with no drag. Count the notches instead of going by feel; too tight causes drag and heat, too loose leaves a long pedal.
5. Refit the plug and repeat on the other side.
6. Check cable adjustment: Press the pedal with firm force and count the clicks. If the count is outside the factory range, adjust the cable at the adjuster under the car, then recheck.
7. Test that both rear wheels turn freely with the pedal released, then check the car holds on an incline.

If the cable adjuster is already at the end of its travel, the cable is stretched and should be replaced rather than forced. Do not soak parking brake cables in penetrating oil or solvent. Many modern cables use stainless wire in a nylon-lined sheath, and oil attracts grime while solvent can wash dirt deeper into the sheath.

Replacing Shoes and What to Do at the Same Time

The best time to service the parking brake on an LS400 is during a rear pad and rotor job, because the rotor has to come off to reach the shoes anyway. With the rotor off, inspect the shoe lining for wear, glazing, cracking or brake fluid or grease contamination, and check the springs, hold-downs and adjuster screw.

• Replace shoes as a set on both sides if the lining is thin, contaminated or separating.
• Clean and lubricate the adjuster screw so it turns freely, and replace it if the threads are corroded.
• Replace fatigued springs and hold-downs. A new hardware kit is inexpensive insurance against rattles.
• Check the drum surface inside the rotor hat. If you are replacing rear rotors, the new rotors come with a fresh drum surface too; see our brake rotors.
• Freeing a stuck rotor: Remove the access plug and back the star wheel off a few clicks while turning the rotor. If drag increases, you are turning it the wrong way. Do not hammer a rotor off before backing off the adjuster, or you can bend the parking brake parts.

If you are doing the rear pads at the same time, match the pad to the year. For 1993-1994 cars we carry the EBC Redstuff ceramic rear pads for the 1993-1994 LS400 and the EBC Greenstuff 2000 rear pads for the 1993-1994 LS400. For the front of a 1995-2000 car, there are the EBC Redstuff ceramic front pads and the EBC Yellowstuff front pads. Browse all brake pads, brake shoes and brake hardware kits.

How Hard Is the Job?

A shoe and cable adjustment is a manageable driveway job with jack stands, a brake spoon and some patience lining up the access hole. Replacing the parking shoes is harder: you remove the caliper and rotor, then deal with springs and hold-downs in a tight space, so photograph the assembly before taking it apart. Replacing a cable adds routing work under the car. If the shoes are soaked with fluid or grease from a leaking seal, fix the leak first and replace the contaminated parts; cleaning soaked lining does not restore it.

After new shoes go in, bed them in as described in the factory service manual before relying on them on a steep grade, and recheck the pedal travel.

Frequently Asked Questions

Does the LS400 use the rear calipers as the parking brake?

No. The 1993-2000 LS400 uses separate drum shoes inside the rear rotor hats. The rear calipers and pads only handle normal braking.

Why did my parking brake get weak after a rear brake job?

The shoes were probably not re-adjusted after the rotors went back on. New rotors and a backed-off adjuster leave extra clearance. Adjust the shoes through the access hole, then check the cable.

Can I just tighten the cable to fix a long pedal?

Only after the shoes are adjusted. Tightening the cable to cover loose shoes gives a firm pedal but weak holding, and can leave the brake dragging on one side.

Are the parking brake shoes the same for all LS400 years?

No. Lexus used different shoe assemblies for 1990-1994 and 1995-2000 cars, with separate left and right parts. Order by model year.

How do I know if the parking brake is holding correctly?

The owner's manual check is to confirm proper pedal travel and that the car holds securely on a safe incline with only the parking brake applied.

Why won't my LS400 rear rotor come off?

The parking shoes are likely gripping a rusted or lipped drum surface. Remove the access plug and back off the star wheel before trying to remove the rotor.

Sources

1. 1998 Lexus LS400 Owner's Manual - pedal set and release lever, reminder light, incline and pedal travel check
2. Genuine Lexus LS400 parking brake shoes - separate shoe assemblies for 1990-1994 (UCF10) and 1995-2000 (UCF20), left and right
3. Brake and Front End: Adjusting Parking Brakes - drum-in-hat design, star wheel adjustment, shoes before cable, cable care and replacement
4. Brake and Front End: Removing a Rear Rotor Stuck on the Parking Brake - backing off the adjuster to free a rotor