2007-2012 Acura RDX Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2007-2012 Acura RDX sets its parking brake with a foot pedal that pulls cables to a small set of drum brake shoes hidden inside the hat of each rear rotor. When the pedal goes nearly to the floor, the brake will not hold on a hill, or the red brake light stays on after release, the cause is almost always shoe adjustment, stretched or seized cables, or worn parking brake shoes - and the fix starts at the rear wheels, not the pedal.

How the First-Generation RDX Parking Brake Works

Acura's owner's manual describes the first-generation RDX as having disc brakes at all four wheels, and the parking brake is a separate pedal: you push it down with your foot to apply it and push it again to release it. That pedal does not squeeze the rear calipers. Instead, it pulls a front cable that feeds a left rear and a right rear cable, and each rear cable operates a pair of parking brake shoes.

Those shoes sit inside the center "hat" of the rear rotor. The inside of that hat is machined as a small drum, and the shoes expand against it. This layout is called a drum-in-hat parking brake. Acura lists a dedicated parking brake shoe for the RDX in its genuine parts catalog, along with separate front, left rear and right rear parking brake cables, which confirms the setup.

Why this matters to you as an owner: the rear disc pads and the parking brake shoes are two separate wear items that happen to live in the same corner of the car. New rear pads do nothing for a weak parking brake, and a worn rotor hat can weaken the parking brake even when the pads are fresh.

Common RDX Parking Brake Problems and Their Symptoms

Pedal travels too far or will not hold on a slope

This is the most common complaint. The shoes wear slowly, the cables stretch, and the pedal has to travel farther before the shoes contact the drum. Acura's owner's manual warns that if the parking brake is not set firmly the vehicle may roll when parked on an incline, and it tells you to set the parking brake before you shift into Park so the vehicle does not put pressure on the transmission's parking mechanism. A parking brake that cannot hold the RDX on a driveway slope puts that load back on the transmission every time you park.

Red brake light or "RELEASE PARKING BRAKE" stays on

The red parking brake and brake system indicator comes on as a reminder whenever the parking brake is applied, and on Technology Package models the multi-information display shows a "RELEASE PARKING BRAKE" message. The manual states that a beeper sounds if you drive with the brake not fully released. If the light stays on after the pedal is fully released with the engine running, or comes on while driving, Acura says there could be a problem with the brake system - most often low brake fluid. Check the reservoir before blaming the parking brake switch. Low fluid usually means worn pads or a leak, not a parking brake fault.

Dragging, heat or a burning smell from the rear

If a rear cable rusts inside its sheath, it can stay partly applied after you release the pedal. The shoes then drag on the drum. Acura warns that driving with the parking brake partially set can overheat or damage the rear brakes. Signs include one rear wheel much hotter than the other after a drive, a burning smell, reduced fuel economy, or a slight pull when coasting.

Parking brake is weak after new rear rotors

A new rear rotor has a fresh drum surface, while the shoe adjuster was set for the old, worn one. If the shoes are not re-adjusted and bedded in, the parking brake can feel weak, or the rear wheel can be hard to turn by hand. Either way, the shoes need adjusting whenever the rear rotors are changed.

What Causes the Parking Brake to Lose Adjustment

• Shoe wear. Every time the parking brake is applied while the vehicle creeps, or driven with it partly on, the lining wears. Drum-in-hat shoes are not adjusted by normal service braking, so wear shows up as more pedal travel.
• Cable stretch. The cables stretch slightly over years of use, adding slack between the pedal and the shoes.
• Disuse and corrosion. Owners who never use the parking brake often have the worst problems. Salt and moisture seize the cables and the shoe adjuster, and a rust ridge forms on the drum surface.
• Contamination. Grease or brake fluid on the shoe lining will make it slip no matter how well it is adjusted. Contaminated shoes must be replaced.
• Worn drum surface. If the rotor hat is badly scored or worn, the shoes cannot make full contact.

Acura treats this as a routine inspection item. The Maintenance Minder main items for the 2007 RDX include "Check parking brake adjustment" right alongside inspecting the front and rear brakes, so a car with regular service should have it looked at periodically.

How to Adjust the 2007-2012 RDX Parking Brake

Adjustment on a drum-in-hat system is done in two stages, and the order matters. Adjusting only the cable to make up for worn shoes is the most common mistake: it shortens pedal travel for a while, but it can leave the shoes lightly applied and cause drag.

1. Safety first. Park on level ground, chock the front wheels, and support the rear of the vehicle on jack stands. Release the parking brake fully.
2. Adjust the shoes first. With the rear wheels off, set the shoe adjuster inside each rear brake so the shoes just begin to drag on the drum, then back it off until the rotor turns freely by hand. Follow the factory service manual for how to reach the adjuster on your vehicle.
3. Then adjust the cable. Take up cable slack at the adjuster only after the shoes are set, until the pedal applies within the travel range given in the factory service manual.
4. Check for drag. With the pedal fully released, both rear wheels must spin freely and the red indicator must go out.
5. Bed the shoes if new. New shoes or new rotors need a burnish procedure before they reach full holding power. Follow the procedure in the service manual rather than improvising one on public roads.

Torque the caliper bracket and wheel fasteners to the values in the factory service manual when you reassemble. If a cable is seized, adjusting it will not help - it has to be replaced. The RDX uses separate left and right rear cables, so a single seized side can be replaced on its own.

What to Replace at the Same Time

Because the parking brake lives inside the rear rotor, most parking brake work happens with the rear brakes already apart. That is the time to handle the related parts:

• Rear rotors. If the rotor hat is rusted, ridged or scored, the parking brake shoes will never hold well. Our EBC USR slotted rear rotor set for the 2007-2009 RDX provides a fresh friction face and a fresh drum surface in one job. Browse more options in our brake rotors collection.
• Rear pads. If you are removing the rotors, inspect the pads. For 2010-2012 models we carry EBC Yellowstuff rear brake pads for the 2010-2012 RDX, and you can compare other compounds in our brake pads collection.
• Parking brake shoes and hardware. Replace shoes that are glazed, thin or contaminated, along with the springs and adjuster hardware. Old springs lose tension and adjusters seize. See our brake hardware kits and brake shoes.
• Brake fluid. Acura specifies Honda Heavy Duty Brake Fluid DOT 3 for this RDX, allows DOT 3 or DOT 4 from a sealed container only as a temporary replacement, warns that DOT 5 is not compatible, and calls for replacing the brake fluid every 3 years regardless of mileage. If the fluid is due, flush it while the rear brakes are apart.

If you are doing a full brake refresh, the front axle often wears faster. We carry EBC Yellowstuff front brake pads for the 2007-2009 RDX and EBC USR slotted front rotors for the 2007-2009 RDX.

How Hard Is the Job?

Checking pedal feel and whether the RDX holds on a slope takes a minute. A basic cable adjustment is a moderate DIY job with the vehicle safely supported. Replacing parking brake shoes is more involved: the rear caliper and bracket come off, the rotor comes off, and the shoe springs and hold-downs take patience and the right tools. Many experienced home mechanics do it; if you have never worked on drum brake hardware, take photos before disassembly and do one side at a time so the other side serves as a reference.

Take the vehicle to a shop instead if the brake fluid level is low, the red brake light comes on while driving, or the service brake pedal feels soft or sinks. Those point to the hydraulic system, and Acura's manual advises having it inspected promptly.

Frequently Asked Questions

Does the 2007-2012 Acura RDX have an electronic parking brake?

No. The first-generation RDX uses a foot-operated parking brake pedal. You push the pedal down to apply it and push it again to release it, and it works mechanically through cables to shoes inside the rear rotors.

Will new rear brake pads fix a weak parking brake?

No. On this RDX the parking brake uses its own shoes inside the rotor hat, separate from the rear disc pads. A weak parking brake is fixed by adjusting or replacing the shoes and cables, and sometimes by replacing a worn rotor.

Why is my RDX parking brake weak after I replaced the rear rotors?

The new rotor has a fresh drum surface, and the shoe adjuster is still set for the old one. Re-adjust the shoes, then the cable, and burnish the shoes following the service manual procedure.

Can I drive with the brake warning light on if the parking brake is released?

Acura's guidance is that if the light stays on after you fully release the parking brake, or comes on while driving, the brake fluid level is probably low. If the pedal feels normal, check the fluid at your next stop and have the system inspected. If the brake pedal feels abnormal, take immediate action and get the vehicle checked.

What brake fluid does the first-generation RDX use?

Acura specifies Honda Heavy Duty Brake Fluid DOT 3. DOT 3 or DOT 4 from a sealed container is allowed as a temporary replacement, and DOT 5 must not be used. The fluid should be replaced every 3 years regardless of mileage.

Should I use the parking brake every time I park?

Yes. Acura tells owners to always use the parking brake and to set it before shifting into Park. Regular use also keeps the cables and shoe hardware moving so they are less likely to seize.

Sources

1. 2007 Acura RDX Owner's Manual (Honda/Acura) - foot-operated parking brake pedal, indicator and RELEASE PARKING BRAKE message, parking tips, four-wheel disc brakes, Maintenance Minder parking brake check, DOT 3 fluid and 3-year replacement
2. Genuine Acura RDX Parking Brake Shoe (Acura Parts Warehouse) - dedicated parking brake shoes on the RDX, confirming the drum-in-hat design
3. Genuine Acura RDX Parking Brake Cable (Acura Parts Warehouse) - separate front, driver-side rear and passenger-side rear parking brake cables