2004-2010 Chevrolet Cobalt Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

Most Chevrolet Cobalt parking brake complaints come down to three things: a stretched or seized cable, rear brakes that have drifted out of adjustment, or a warning light that stays on because the lever is not fully down. The fix is usually a cable adjustment at the lever, a clean-and-adjust of the rear brakes, or a new cable, not a whole new brake system. Here is how the Cobalt system is built, how to diagnose it, and how GM tells a technician to adjust it.

How the Cobalt Parking Brake Works

The Cobalt uses a hand lever between the front seats. GM's owner information says to hold the brake pedal down, then pull the lever up to set it. To release it, hold the pedal down, lift the lever slightly until you can press the release button, then lower the lever all the way while holding the button in.

Under the car, GM's service manual describes a three-cable system: one front cable that runs from the lever to an adjusting nut, and separate left and right rear cables that run under the body, clip into retainers at the rear axle trailing arm pivot, and end at the rear brakes. What they end at depends on the car:

• Rear drum cars: the rear cable passes through the backing plate and pulls a parking brake lever attached to one of the brake shoes. A strut between the shoes spreads them against the drum.
• Rear disc cars: the rear cable attaches with caliper-mounted guides and pulls the park brake lever on the caliper. GM's manual also covers parking brake shoes that sit inside the rotor on disc-brake cars, so look at your own rear brakes before ordering parts. Rear discs were used on the performance SS versions, which is why rear pads for the Cobalt are listed for the SS.

Because the front cable feeds both rear cables through one adjuster, a single adjustment at the lever sets both rear wheels.

Common Cobalt Parking Brake Problems and Symptoms

About that warning light: the owner information says the brake system warning light comes on whenever the parking brake is set with the ignition on, and a chime plus a PARKING BRAKE message appear if the car is moving faster than 5 mph with it applied. If you see that message while the lever is down, check that the lever is actually seated at the bottom of its travel, then check the fluid level, since the same red lamp also warns of hydraulic problems.

Do not ignore dragging. GM warns that driving with the parking brake on can overheat the brake system and cause premature wear or damage. A cable that does not fully return acts like a lightly applied parking brake, and it will glaze rear shoes or pads and heat the drum or rotor on that side.

How to Diagnose It at Home

1. Watch the lever travel. A lever that has started coming up noticeably higher than it used to is telling you slack has crept into the system.
2. Test on a gentle slope. With a helper ready at the brake pedal, see whether the lever alone holds the car with the transmission in neutral.
3. Check for drag. Raise the rear safely on stands, release the lever, and spin each rear wheel by hand. Both should turn freely with only light brake contact.
4. Watch the cables. With a helper working the lever, look at each rear cable where it enters the drum backing plate or caliper. Both should move. A cable that does not move, or moves and does not return, is seized.
5. Look at the rear friction. If the rear shoes or pads are worn, adjust nothing until they are replaced. Adjusting the cable to make up for worn linings only hides the real problem.

How GM Says to Adjust the Cobalt Parking Brake

The adjuster is the nut on the front cable threaded rod, under the lever boot in the console. For rear disc cars, GM's procedure goes like this:

1. Remove the lever boot to reach the adjusting nut.
2. Loosen the nut enough to take all tension off the front cable, raise the car, and confirm the rear rotors turn without drag.
3. Tighten the nut until all slack is gone from the front cable, then keep going until one of the park brake levers on the rear calipers just lifts off its stop.
4. Back the nut off until that lever rests on its stop again, then back it off one more full turn.
5. Apply and release the parking brake three to five times.
6. Check the result: at three clicks the rear wheels should be difficult to turn but not locked; at four clicks they should be locked. Fully released, they should spin freely with no drag.
7. Reinstall the boot.

That final backing-off step matters. Setting the cable so the caliper lever is held off its stop leaves the rear brakes partly applied all the time.

On rear drum cars the cable is not the primary adjustment. GM describes the drum shoes as self-adjusting, with the automatic adjusters working when the brakes are applied. When the drums are serviced, GM has the technician release all cable tension at the front adjusting nut first, set the shoe-to-drum clearance with a drum-to-shoe gauge to 0.015 inch, and apply the brakes two or three times to seat and center the shoes. Only then is the cable taken up. If you tighten the cable on a drum car whose shoes are far out of adjustment, the lever will feel better but the service brakes will still be under-adjusted.

Parts to Replace and What to Do at the Same Time

• Seized or frayed rear cable: replace that cable. GM's procedure notes the rear cable is held at the trailing arm pivot by a C-shaped retainer and warns not to pull on the cable to release it. The job means removing interior trim and the rear wheels, so plan an afternoon.
• Worn rear drum shoes: replace the shoes as an axle set with fresh springs from a brake hardware kit. Tired return springs and a weak parking brake strut spring are a common reason drum parking brakes feel weak. Shop rear brake shoes.
• Rear disc cars: replace pads as a pair and make sure the caliper park brake lever moves freely back to its stop. For 2007-2010 Cobalt SS with Brembo brakes we carry Hawk HPS 5.0 rear brake pads for the Cobalt SS, and for the 2008-2010 SS turbo there are EBC Redstuff ceramic rear pads.
• Always: readjust the parking brake after any rear brake work, then verify the three-click and four-click checks.

For everything else on the car, browse all brake parts.

A Safety Note: The Cobalt Ignition Key Recall

The parking brake plays a role in one of the most widely known Cobalt recalls. Under NHTSA campaign 14V-171, GM recalled all 2005-2010 Cobalts, along with related GM models, because the ignition key could be removed when the ignition was not in the Off position. With the key out in that state, an automatic car not in Park, or a manual car without the parking brake set and not in reverse, could roll. GM also determined that all 2005 and some 2006 Cobalts may not conform to FMVSS 114, the federal theft and rollaway standard. The remedy is a replacement ignition cylinder and keys. Until the recall repair is done, GM's instruction to manual-transmission owners is to put the car in reverse and set the parking brake before getting out. Check your VIN on nhtsa.gov if you are not sure your car was repaired, and keep the parking brake in working order either way.

Frequently Asked Questions

Does my Cobalt have rear drums or rear discs?

It depends on the version. Many Cobalts have rear drums, while the performance SS versions use rear discs. Pull a rear wheel and look: a drum is a closed cast housing, a disc has a visible rotor and caliper.

Why does my Cobalt parking brake lever come up so high?

Usually the cable has stretched or the rear linings are worn. Inspect the rear brakes first, then adjust the cable at the nut under the lever boot.

How tight should the parking brake be?

GM's check for rear disc cars is that the rear wheels are hard to turn at three clicks and locked at four clicks, and turn freely with the lever fully down.

Can a stuck parking brake cable ruin my rear brakes?

Yes. A cable that does not return keeps the rear brake lightly applied. GM warns this can overheat the brake system and cause premature wear or damage.

Why is my brake light on even with the parking brake released?

Make sure the lever is fully down. If it is, check the brake fluid level, because the same warning light covers hydraulic faults. A low fluid level can also mean worn pads or a leak.

Is the Cobalt ignition recall related to the parking brake?

Indirectly. Recall 14V-171 fixes an ignition key that could come out when not in Off, which could allow rollaway. GM told manual-transmission owners to use reverse and the parking brake until the repair was done.

Sources

1. Chevrolet Cobalt Owner Information - Parking Brake - set and release procedure, warning light, 5 mph chime, driving-with-brake-on caution
2. Cobalt Service Manual - Parking Brake Cable Adjust - adjusting nut procedure, three-click and four-click checks
3. Cobalt Service Manual - Parking Brake Cable Replace - three-cable layout, routing, C-shaped retainer caution
4. Cobalt Service Manual - Drum Brake Service - self-adjusting shoes, parking brake lever and strut
5. Cobalt Service Manual - Brake Drum Removal and Installation - releasing cable tension, 0.015 inch shoe clearance
6. Cobalt Service Manual - Parking Brake Service, Disc Brakes - parking brake shoe service on disc-brake cars
7. NHTSA - GM Part 573 Defect Report, Recall 14V-171 - ignition key rollaway defect, FMVSS 114, parking brake interim instruction
8. NHTSA - GM Recall Bulletin 14133E - covered models and ignition key remedy