2008-2015 Mercedes-Benz C63 Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2008-2014 W204 Mercedes-Benz C63 AMG, the parking brake is a foot pedal that pulls cables to a pair of small brake shoes working inside the hat of each rear rotor. Those shoes are not self-adjusting, so a pedal that goes too far, a car that creeps on a hill, or a warning that will not clear usually means adjustment, worn shoes or a sticky cable. The 2015 model year brought the W205-based C63, which swaps the pedal for an electric parking brake with its own set of warnings. This guide covers how each system works, what goes wrong, and how to fix it correctly.

How the C63 Parking Brake Works (W204 vs W205)

The W204 C63 uses a drum-in-hat design. The rear disc is a vented rotor (the Brembo catalogue lists a 330 mm by 26 mm vented rear disc for the W204 C 63 AMG), and the inside of its center hat is machined as a small brake drum. Two parking brake shoes sit on the backing plate behind the rotor, and Brembo lists a dedicated parking brake shoe set for this car, which confirms the shoe-and-drum layout. The service brakes (pads and caliper) and the parking brake (shoes and cable) share the rotor but are otherwise separate systems.

The owner's manual for the 2012 C-Class sedan, which includes the C 63 AMG, describes the controls: you depress the parking brake pedal firmly to apply it, and to release it you depress the brake pedal and pull the release handle. With the engine running, a parking brake indicator lamp lights in the cluster while it is applied.

The 2015 W205 C-Class operator's manual describes a different system: an electric parking brake worked by a handle on the dash. You push the handle to apply and pull it to release, and it can also apply and release itself automatically under certain conditions (for example, releasing when the engine is running, the car is in D or R, the belt is fastened and you press the accelerator). If you are unsure which system your car has, look at the footwell: a pedal to the left of the brake pedal means the cable and shoe system.

Common W204 C63 Parking Brake Problems and Symptoms

Because the shoes on the W204 do not adjust themselves, the gap between the shoe lining and the drum surface grows slowly as the linings wear and as rotors are replaced. The problems owners see most often:

• Pedal travels too far or feels weak. The shoes have to move further before they touch the drum. This is the classic sign that adjustment is due.
• Car creeps or rolls on a slope with the pedal set. The shoes are out of adjustment, glazed, contaminated, or worn thin. A weak parking brake is most noticeable on a steep driveway.
• Pedal will not stay down, or the release handle stays out. This points to the pedal assembly latch or the release mechanism rather than the rear shoes.
• Parking brake stays partly applied. A cable that is corroded or kinked may not return, leaving a light drag. Symptoms are a hot rear wheel, a burning smell, or a scraping noise at low speed.
• Grinding or rattling from the rear with the parking brake off. A broken shoe return spring or a loose hold-down lets a shoe touch the drum or rattle.
• "Release Parking Brake" message and warning tone. The 2012 manual says this appears when you are driving with the parking brake applied. If the pedal is fully released and the message persists, the pedal switch or its wiring needs checking.

Also note the manual's warning: engaging the parking brake while the car is moving can lock the rear wheels, and the brake lights do not come on when only the parking brake is applied.

How to Adjust the W204 C63 Parking Brake

Adjustment is done at the star-wheel adjuster between the tops of the two shoes. On drum-in-hat setups like this it can usually be reached with the rotor still on, by turning the rotor until a wheel bolt hole lines up with the adjuster and working it with a flat tool, or by removing the caliper and rotor for full access. The general approach:

1. Chock the front wheels, put the transmission in P, raise and support the rear on stands, and remove the rear wheels. Release the parking brake fully.
2. Confirm the rotor turns freely. If it drags, back the adjuster off before going further and inspect the shoes and cable.
3. Turn the adjuster to expand the shoes until the rotor just drags when turned by hand, then back it off until the rotor spins freely with no rubbing.
4. Repeat on the other side so both sides are even.
5. Check the cable for free play and that it returns fully when released. Cable tension is a separate adjustment; shoe adjustment is always done first.
6. Refit the wheels and torque the wheel bolts to the value in the factory service information, then test the hold on a gentle slope.

If adjustment does not bring the pedal up or the hold back, the shoes need to come out for inspection.

Parking Brake Shoes, Rotors and What to Replace Together

To replace the shoes you remove the rear caliper (hang it by a wire, never by the hose) and the rotor. Look for:

• Lining worn close to the backing, cracked, or separated from the shoe
• Oil or grease on the linings, which often traces back to a leaking rear axle seal; contaminated shoes must be replaced, not cleaned
• Weak, stretched or broken return springs and hold-down hardware
• A seized star-wheel adjuster
• A scored, rusted or glazed drum surface inside the rotor hat

Because the drum is part of the rotor, rear rotor replacement is the natural time to service the parking brake. Fit new shoes and hardware if the old ones are worn, clean the new rotor's drum surface with brake cleaner, and replace rear pads if they are near the end of their life. If you are doing the rear pads at the same time, our EBC Yellowstuff rear brake pads for the W204 C63 and EBC Redstuff rear pads for the W204 C63 6.2L fit the 2008-2013 cars. For hardware and other rear parts, browse brake hardware kits and brake rotors.

New shoes or a new drum surface need bedding in before the parking brake reaches full hold. One published bed-in procedure for rotors with integrated parking brake drums calls for 10 light-to-medium stops from about 20 mph using only the parking brake, then 10 medium-to-heavy stops, allowing about 550 yards between stops for the shoes to cool, and then parking without the parking brake until everything is cool. Do this only on an empty stretch of road, since the brake lights do not work when you slow with the parking brake alone.

2015 W205 C63 Electric Parking Brake Problems

On the W205, most complaints show up as messages rather than a long pedal. Per the 2015 C-Class operator's manual:

• Low voltage matters. The system depends on on-board voltage. With a weak battery or a fault, it may not apply, or an applied brake may not release. A tired battery is worth testing before anything else.
• "Parking Brake See Operator's Manual" with the yellow lamp means a malfunction. The manual's fallback to apply it is: ignition off, press the handle for at least ten seconds, and shift to P. If it cannot be released after switching the ignition off and back on, do not drive on.
• Red lamp flashing with a warning tone while driving means a condition for automatic release was not met and you are driving with it applied; release it manually.
• Noises when parked can be normal: the manual notes the system runs a function test at regular intervals with the engine off.

For rear brake service on the W205, follow the factory service procedure for putting the electric parking brake into its service position, typically with a scan tool, before pushing anything back. Forcing it can damage the actuator. The W205 rear pads we carry include EBC Yellowstuff rear pads for the W205 C63 and EBC Redstuff rear pads for the W205 C63 S.

How Hard Is the Job?

On the W204, a shoe adjustment is an easy job for a home mechanic with stands and a flashlight; the only difficulty is working the adjuster by feel. Shoe replacement is moderate: the springs are fiddly, and you have to remove the caliper and rotor. Cable replacement is more involved because the cables run under the car to the pedal. On the W205, most electric parking brake faults need a scan tool to diagnose, so start with the battery and the manual's reset steps, then move to a shop with Mercedes diagnostics. Either way, confirm the hold on a slope before you rely on it.

Frequently Asked Questions

Does the W204 C63 parking brake adjust itself?

No. The shoes inside the rear rotor hats are adjusted manually at a star-wheel adjuster. Check it whenever the pedal travel grows or when rear rotors are replaced.

Why does my C63 roll with the parking brake set?

Usually the shoes are out of adjustment, glazed, worn, or contaminated with oil from an axle seal. Adjust first; if the hold does not come back, pull the rotors and inspect the shoes.

Do I need new parking brake shoes when I replace rear rotors?

Not always, but inspect them. If the lining is thin, cracked or oily, replace them, and bed in the shoes on the new drum surface either way.

How do I release the parking brake on a 2008-2014 C63?

According to the owner's manual, depress the brake pedal and keep it depressed, then pull the parking brake release handle.

Can I stop the 2015 C63 with the electric parking brake in an emergency?

Yes. The 2015 manual says you can push and hold the handle while driving; braking force increases the longer you hold it, a warning tone sounds, and the brake stays engaged once the car stops.

What pads fit the rear of my C63?

It depends on the generation. See our brake pads range and match the listing to your W204 or W205 C63.

Sources

1. Mercedes-Benz USA - 2012 C-Class Sedan Operator's Manual - foot-operated parking brake apply and release, indicator lamp, "Release Parking Brake" message, rear wheel lock warning
2. Mercedes-Benz USA - 2015 C-Class Sedan Operator's Manual - electric parking brake operation, automatic apply and release, emergency braking, voltage dependence, warning messages
3. Brembo Parts catalogue - W204 C 63 AMG - 330 mm by 26 mm vented rear disc, dedicated parking brake shoe set
4. Parking Brake Shoe Bed-In Procedure, rotors with integrated parking brake drums - bed-in stops, speed, cool-down distance