2006-2011 Chevrolet HHR Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2006-2011 Chevrolet HHR, the front brakes wear first, and it is not close. Most HHRs pair front disc brakes with rear drums, and the front pads do the bulk of the stopping, so you will usually replace front pads and rotors at least once before the rear shoes need attention. The exception is the HHR SS, which uses discs at all four corners, so its rear pads wear on their own schedule and need their own inspection.

How the HHR Brake System Is Laid Out

GM's own owner's manual for the HHR states that the vehicle "has front disc brakes and could have rear drum brakes or rear disc brakes." Which one you have depends on the trim. The standard HHR (LS, LT, and Panel versions) uses a front disc and rear drum setup. The HHR SS, added for 2008, was reviewed at launch as coming with discs all around and larger front brakes than the regular HHR, with ABS standard and a Brembo front brake option that followed shortly after.

Before you order anything, look through the rear wheel spokes. If you see a round, closed drum, you have shoes inside. If you see a flat rotor and a caliper, you have rear discs and need rear pads instead. SS models with the Brembo option also use a different, larger front caliper and rotor, so front parts for a base HHR will not fit them.

Why the Front Brakes Wear First

When any car stops, weight shifts forward onto the front tires. That extra load gives the front tires more grip, so the brake system is proportioned to send more of the braking work to the front axle. On a front-wheel-drive, front-heavy vehicle like the HHR, that bias is strong. The front pads turn more heat into wear on every stop, while the rear drums handle a smaller share and also hold the parking brake.

Drum brake shoes also spread their work over a larger lining area than a disc pad, which is another reason rear shoes on a base HHR commonly outlast several sets of front pads. Driving style matters too: stop-and-go city driving and hilly routes wear the fronts faster, while steady highway driving is easy on both ends.

GM also warns that the balance between front and rear braking depends on using the correct linings. The manual cautions that installing brake linings that are wrong for the vehicle can change the balance between the front and rear brakes for the worse. That is a good reason to stick with parts listed for your exact HHR version.

Symptoms: Front Versus Rear Problems

Front brake wear signs

• High-pitched squeal while driving. The HHR's disc brake pads have built-in wear indicators. GM describes the sound as a high-pitched warning that can come and go or be heard all the time the car is moving, except when you press the pedal firmly. That sound means the pads are due now.
• Pulsation in the pedal or steering wheel. This usually points to front rotor thickness variation or uneven deposits. GM notes that properly torqued wheel nuts help prevent brake pulsation, so uneven lug nut tightening after a tire job is a common cause.
• Grinding. Metal-on-metal contact means the pad material is gone and the rotor is being damaged. Replace pads and rotors together at this point.

Rear brake wear signs

• Rubbing or scraping from the rear. Rear drum brakes have no wear indicators. GM's guidance is that if you hear a rear brake rubbing noise, have the rear linings inspected immediately.
• Weak parking brake. On drum-equipped HHRs, the parking brake lever between the seats works the rear brakes. If the lever pulls up high before it holds, the shoes may be worn or the self-adjuster may be stuck.
• Low brake fluid. The manual explains that fluid level drops as linings wear and comes back up when new linings are installed. A low reservoir with the warning light on is a sign to inspect all four corners and check for leaks, including a seeping rear wheel cylinder.

Inspection Schedule GM Recommends

The HHR owner's manual gives a simple routine that catches most problems early:

1. When the tires are rotated, inspect the brake pads for wear.
2. On drum-equipped models, remove and inspect the rear brake drums each time the tires are removed for rotation or changing.
3. When the front brake pads are replaced, have the rear brakes inspected too.
4. Always replace brake linings as complete axle sets, both sides of the same axle at once.

The HHR's brakes adjust for wear each time you apply them, so there is no routine manual adjustment. A drum brake whose self-adjuster has seized, however, will slowly lose pedal height and parking brake hold, which is exactly what the rotation-time inspection is meant to catch.

What to Replace, and What to Replace With It

Front brakes (non-SS models)

The most common HHR brake job is front pads and rotors. Replacing rotors along with pads gives the new pads a flat, clean surface to bed into and removes the most common source of pulsation. Our 2006-2011 Chevrolet HHR front brake kit includes two front rotors, ceramic pads and installation hardware. SS owners, especially with the Brembo package, should confirm their caliper and rotor size before ordering, since the larger system uses different parts. You can also shop brake pads and brake rotors separately, or browse ceramic brake pads if low dust is a priority.

While the front is apart, replace the abutment clips if they are rusted or bent, clean and lubricate the caliper slide pins with silicone brake grease, and look at the rubber brake hoses for cracks or swelling. A sticking slide pin is a leading cause of one pad wearing much faster than the other. Fresh clips come in our brake hardware kits, and worn hoses can be replaced from our brake hoses collection.

Rear drums (non-SS models)

When the rear shoes finally need replacing, do the full job: shoes, return and hold-down springs, and inspect the drums for scoring, a raised lip or heat checking. Check each wheel cylinder by gently peeling back its boots; any fluid behind them means the cylinder should be replaced. Rear brake shoes are the core part here, and a new hardware kit is inexpensive insurance against a stuck adjuster.

Rear discs (SS)

On the SS, treat the rear like a smaller version of the front: pads and rotors in axle sets, clean and lubricated slides, and a check of the parking brake function afterward.

Brake fluid

GM specifies DOT 3 hydraulic brake fluid for the HHR, from a new, sealed container. On manual transmission models, the brake master cylinder and the clutch hydraulic system share the same reservoir, so the wrong fluid can affect both. A bleed or flush is a sensible add-on to any job where you replace a caliper, hose or wheel cylinder.

How Hard Is the Job?

Front pads and rotors on a base HHR are a moderate DIY job for someone with basic hand tools, a jack and stands, and a torque wrench. The caliper and bracket come off, the rotor slides off the hub, and the reverse order goes back together. Torque the caliper and bracket bolts to the factory service manual value, and torque the wheel nuts to the owner's manual specification of 100 lb ft in the proper sequence.

Rear drum shoes take more patience. Step-by-step repair guides for the 2006-2011 HHR list sockets, a pry bar, needle-nose pliers, brake cleaner and brake grease for the rear job, and the springs and adjuster must go back exactly as they came out. Do one side at a time so the other side stays assembled as a reference. After the job, pump the pedal until it is firm before driving, then bed the new pads or shoes with a series of moderate stops.

One safety note from NHTSA's recall records: HHRs were covered by ignition key recall 14V171000, where the key could be removed with the ignition not in the off position, which could allow the vehicle to roll away if the transmission was not in park or, on manual models, if the parking brake was not set. When you work on any HHR, set the parking brake and chock the wheels, and check your VIN on nhtsa.gov to confirm the recall work was done.

Frequently Asked Questions

Does my Chevy HHR have rear drum or rear disc brakes?

Most HHRs, including the LS, LT and Panel models, have rear drum brakes. The HHR SS has rear disc brakes. Look through the rear wheel: a round closed drum means shoes, a flat rotor with a caliper means pads.

Should I replace front and rear brakes at the same time on an HHR?

Not automatically. The fronts almost always wear out first. GM recommends inspecting the rear brakes whenever the front pads are replaced, and replacing the rears only when they are worn, leaking or damaged.

Why don't my rear HHR brakes squeal when they are worn?

Rear drum brakes on the HHR do not have wear indicators. That is why GM recommends pulling the drums at every tire rotation and having the rear linings checked right away if you hear a rubbing noise.

Do front brake parts from a regular HHR fit the HHR SS?

Not reliably. The SS uses larger front brakes, and the Brembo option uses a different caliper and rotor. Match the part to your exact trim and brake package before ordering.

What brake fluid does a Chevy HHR use?

GM specifies DOT 3 hydraulic brake fluid from a sealed container. On manual transmission HHRs, the clutch hydraulic system uses the same reservoir and the same fluid.

Why does my HHR shake when braking after new tires?

Uneven lug nut torque is a common cause. GM notes that properly torqued wheel nuts help prevent brake pulsation. If re-torquing in sequence does not fix it, the front rotors likely have thickness variation and should be replaced.

Sources

1. 2010 Chevrolet HHR Owner Manual (GM) - front disc with rear drum or rear disc, wear indicators, rear drum inspection at rotation, axle-set replacement, self-adjusting brakes, DOT 3 fluid and shared clutch reservoir, 100 lb ft wheel nut torque
2. The Auto Channel: 2008 Chevrolet HHR SS Review - base HHR uses rear drums, SS uses discs all around with larger fronts, standard ABS and Brembo front option
3. 1A Auto: How to Replace Rear Brakes 2006-2011 Chevrolet HHR - rear drum brakes on the HHR and tools used for the rear brake job
4. NHTSA Recalls: Chevrolet HHR - recall 14V171000 ignition key removal and rollaway risk involving the parking brake