2012 Buick Regal Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2012 Buick Regal the front brakes almost always wear out first, usually well before the rears, because the front axle does most of the stopping work. The rears last longer, but they are not free to service: the rear brakes also carry the electric parking brake, so they need the correct release procedure before you push the caliper pistons back. Replace pads as complete axle sets, and check the rotors on the same axle while you are there.

How the 2012 Regal brake system is laid out

Every 2012 Regal has disc brakes at all four corners. The owner's manual states plainly that the vehicle has disc brakes and that the pads have built-in wear indicators. There are no rear drums to adjust on this car.

What changes between trims is the front hardware. The Regal GS was launched with what GM described as a large-diameter four-wheel disc system with four-piston Brembo front calipers. Other 2012 Regals use conventional sliding front calipers. The two front setups take different pads and rotors, so the first question before ordering anything is: does your car have the Brembo front calipers? Look through the front wheel spokes. A Brembo caliper is a fixed, multi-piston unit with the Brembo name cast or printed on it.

At the rear, the Regal uses an Electric Parking Brake (EPB) instead of a lever or foot pedal. The switch is on the center console. The EPB applies the rear brakes, which is why rear brake service on this car involves one more step than an older sedan with a cable handle.

Why the front brakes wear out first

When you brake, the car's weight pitches forward onto the front tires. That gives the front tires more grip, so the brake system is built to send most of the braking force to the front. More force means more heat and more friction material worn away, which is why front pads on nearly any front-engine sedan are replaced more often than rears. The Regal is front-wheel drive with the engine and transaxle over the front axle, which adds to that forward bias.

GM's own manual warns about this balance. It says installing disc brake pads that are wrong for the vehicle can change the balance between the front and rear brakes for the worse. That is the practical reason not to mix a very aggressive front compound with a mild rear one, or the reverse, unless the pads are made as a matched set for this car.

A few things can flip the usual pattern and wear the rears faster:

• A dragging rear caliper. A seized slide pin or a sticking piston keeps the pad on the rotor. One rear pad worn much thinner than its partner is the tell.
• Driving with the parking brake partly applied. The manual cautions that driving with the parking brake on can overheat the brake system and cause premature wear. If the parking brake status light keeps flashing, the EPB may be only partly applied or released.
• Stability control intervention. Traction and stability systems apply individual brakes, including rears, which adds some rear wear for drivers who trigger them often.

On Regals equipped with eAssist, regenerative braking takes some energy from the moving car and stores it in the high-voltage battery, and the manual notes it captures more energy as more brake pedal is applied. That shares part of the stopping work with the friction brakes, so pad life on those cars can differ from a non-eAssist Regal driven the same way.

Symptoms and how to tell which end needs work

• High-pitched squeal while driving that stops when you press the pedal hard. The manual describes exactly this as the built-in wear indicator: a high-pitched warning sound when the pads are worn, which can come and go or be constant except under firm braking. Find which wheel it comes from before ordering parts.
• Grinding. The pad backing plate is on the rotor. That axle needs pads and rotors, not pads alone.
• Pulsation in the pedal or steering wheel. A pulse felt in the steering wheel points to the front rotors. A pulse felt mostly through the seat and pedal with a steady steering wheel often points to the rears. GM also notes that properly torqued wheel nuts help prevent brake pulsation, so uneven lug torque can cause it too.
• Low brake fluid warning. The manual explains that fluid level drops as pads wear and comes back up when new linings go in. A low level with worn pads is expected; a low level with thick pads points to a leak.
• Parking brake lights. A continuously flashing parking brake status light means the EPB is only partly applied or released, or has a fault. The manual says not to drive the car in that condition.

The simplest check is visual. With the wheels off during a tire rotation, compare pad thickness at all four corners and look at the inner pads too, since the inner pad on a sliding caliper often wears faster and cannot be seen from outside.

What to replace, and what goes with it

GM's rule in the owner's manual is that brake linings should always be replaced as complete axle sets. That means both front wheels together or both rear wheels together, never one side only.

Front service: If the pads are at the wear indicator and the rotors are smooth, pads alone may do. If there is grinding, deep scoring, heat spots or pulsation, replace the rotors with the pads. For a GS or any Regal with the Brembo front calipers, use parts made for that setup, such as this Hawk Talon drilled and slotted front rotor set for the 2012 Regal with Brembo calipers. For standard-caliper cars, shop replacement brake rotors and ceramic brake pads by exact fitment.

Rear service: Rear pads last longer but corrode and stick in wet or salted climates. Replace rear rotors when they are worn, rusted on the friction face or out of spec. Clean and lubricate the slide pins and replace the abutment clips from a brake hardware kit.

At the same time:

• New pad hardware and fresh caliper slide-pin grease on every axle you service.
• Inspect the flexible brake hoses for cracks and swelling.
• Check the fluid type on the reservoir cap. The manual says the reservoir is filled with either DOT 3 or DOT 4 as indicated on the cap, and to use only new fluid of that type from a sealed container. For DOT 4 cars, GM recommends flushing the fluid every two years.
• Do not top off the fluid before the job. The manual warns that fluid added when linings are worn will be too much once new linings are installed.

If you want one order that covers both ends, browse Power Stop brake kits and the full brake parts catalog, and match the listing to Brembo or standard front calipers.

How hard is the job

Fronts: A standard-caliper front brake job is a normal driveway job for someone with jack stands, a torque wrench and basic hand tools. On Brembo cars, the fixed four-piston caliper does not slide; the pads come out of the caliper body, and all pistons must be pushed back evenly. It is still manageable, but take care not to cock a piston in its bore.

Rears: The rear job is where the EPB matters. The electric parking brake must be released and placed in its service position using the procedure in the factory service information before you retract the rear pistons. Forcing a piston back against an applied EPB can damage the mechanism. If you are not sure of the procedure for your car, this is the end to hand to a shop with a scan tool. The manual also notes the EPB cannot be applied or released with insufficient electrical power, so a weak battery can stall the job.

Finishing up: Torque the wheel nuts evenly in the proper sequence. The 2012 owner's manual lists wheel nut torque as 150 N.m (110 lb ft). Pump the pedal to seat the pads before moving the car, then bed in the new pads with several moderate stops.

While the rear is apart: NHTSA lists recalls for rear suspension toe links on 2012-2013 Regals sold or registered in many salt-belt states, including a 2026 expansion for Regal Turbo and GS trims (campaign 26V113). Corroded toe links can thin and fracture. The remedy is free toe link and adjuster fastener replacement at a dealer, so check your VIN for open recalls around a rear brake job.

Frequently Asked Questions

Do I need to replace front and rear brakes on my 2012 Regal at the same time?

No. Each axle is serviced on its own schedule, and the fronts usually go first. What GM does require is that pads be replaced as complete axle sets, so both fronts or both rears together.

How do I know if my Regal has Brembo brakes?

Look at the front calipers through the wheel. Brembo calipers are fixed four-piston units with the Brembo name on them and came on the Regal GS. If your front caliper is a sliding type, order standard-caliper parts.

Why is only one of my rear pads worn down?

That points to a sticking caliper slide pin, a seized piston or a parking brake that is not fully releasing. Fix the cause when you replace the pads, or the new ones will wear the same way.

Can I push the rear caliper pistons back with a C-clamp?

Not until the electric parking brake has been released into its service position using the factory procedure. Forcing the piston against the EPB mechanism can damage it.

What brake fluid does a 2012 Buick Regal use?

The owner's manual says DOT 3 or DOT 4, as marked on the reservoir cap. Use only new fluid of the type shown on your cap from a sealed container, and never let any mineral-based oil into the system.

Is a squeal from my Regal always worn pads?

Not always. GM notes that some driving conditions or climates can cause squeal when the brakes are first or lightly applied without anything being wrong. A squeal that happens while driving and stops under firm braking is the classic wear-indicator sound.

Sources

1. 2012 Buick Regal Owner Manual (GM) - disc brakes and wear indicators, axle-set replacement, pad balance warning, DOT 3/DOT 4 fluid, two-year DOT 4 flush, EPB operation and warning lights, eAssist regenerative braking, 150 N.m (110 lb ft) wheel nut torque
2. NHTSA recalls for the 2012 Buick Regal - rear toe link corrosion recalls 20V764, 21V00F and 26V113; no brake-system recalls listed
3. GM release: Buick Regal GS (PR Newswire) - GS large-diameter four-wheel disc system with four-piston Brembo front calipers, four-channel ABS and StabiliTrak