2012-2013 Buick Regal Brake Caliper Problems and Replacement

By Core Brake Parts Tech Team — Circleville, OH warehouse

Caliper trouble on a 2012-2013 Buick Regal usually shows up as a pull to one side, a hot or smoking wheel, uneven pad wear, or a soft pedal from a leaking piston seal. The fix is to identify which brake system your Regal has (the GS uses four-piston Brembo front calipers, other trims do not), replace the failed caliper, and renew the pads and rotors on that axle at the same time. There are no NHTSA safety recalls on the brakes of either model year, so this is a normal wear-and-age repair, not a factory defect.

How the Regal brake system is laid out

The 2012 Regal owner manual states that the car has disc brakes, and that the pads carry built-in wear indicators that make a high-pitched sound when new pads are needed. Every Regal of these years also has an Electric Parking Brake (EPB), switched from the center console, rather than a hand lever or foot pedal.

There are two front caliper designs to know about:

• Regal GS: GM's launch release for the 2012 Regal GS describes a large-diameter four-wheel disc system with big four-piston Brembo front calipers, paired with a four-channel ABS.
• Other Regal trims (including eAssist cars): these use a conventional front caliper, not the Brembo unit. Pads, rotors and calipers for the two systems are not interchangeable.

Before you order anything, confirm which caliper is on the car. The Brembo calipers are easy to spot through the GS wheels by the Brembo name on the caliper body. If you are not sure, check the build options for your VIN with a dealer or on the option label in the car. Ordering by year and model alone is the most common mistake on this platform.

Symptoms of a bad caliper

A caliper's job is simple: push the pads against the rotor when you press the pedal, and let go when you release it. Almost every caliper failure is one of those two things going wrong.

• Pulling to one side under braking. One caliper is applying harder or softer than the other, often from a sticking piston or seized slide.
• Pulling or drag while cruising. A caliper that does not release keeps the pads on the rotor. You may notice the car coasting poorly or a slight pull with no brake applied.
• One wheel much hotter than the others. After a drive, a dragging caliper leaves that wheel noticeably hotter and often smelling of hot brakes. Do not touch the rotor to test; hold your hand near the wheel or use an infrared thermometer.
• Uneven pad wear. One pad worn far thinner than its partner, or one side of the car worn much more than the other, points to a caliper problem rather than normal wear.
• Soft or sinking pedal, or fluid on the inside of the wheel. A leaking piston seal lets fluid out. The owner manual advises seeing a dealer if the pedal does not return to normal height or pedal travel increases rapidly.
• Brake fluid warning. The manual notes the brake warning light comes on when the fluid falls low. A leak, not pad wear alone, is the likely cause if the level drops quickly.

Do not confuse caliper symptoms with the pad wear sound. The manual describes the wear indicator as a high-pitched noise that can come and go while driving, and says some brake squeal on first or light applications does not mean anything is wrong. Grinding, on the other hand, usually means the pads are gone and metal is contacting the rotor.

What causes caliper failure on a Regal of this age

A 2012-2013 Regal is now well over a decade old, and most caliper trouble comes from age and moisture rather than design:

• Old brake fluid. Brake fluid absorbs moisture over time, and that moisture corrodes pistons and bores from the inside. The owner manual recommends flushing and refilling DOT 4 systems every two years. If your car has never had a fluid flush, corroded pistons are much more likely.
• Torn dust boots. Once the rubber boot around a piston splits, road water and salt reach the piston surface. Rust then makes the piston stick in its bore.
• Seized slide pins (non-GS calipers). Conventional calipers slide on pins that need clean, lubricated bores. Dry or rusted pins leave the caliper cocked, which wears the pads at a taper and causes drag.
• Wrong fluid. The manual warns that even a few drops of mineral-based oil such as engine oil in the hydraulic system can damage parts badly enough that they must be replaced. Seals swell and calipers then stick or leak.

The fix: replacing the caliper and what goes with it

A leaking or seized caliper is replaced, not patched. On the non-GS system, a remanufactured or new loaded caliper is the usual repair. On a GS, the Brembo four-piston caliper is a more expensive unit, so owners sometimes rebuild it with a seal kit if the bores are clean; if the bores are pitted, replace it. You can browse replacement units in our brake calipers collection.

Replace these at the same time:

• Pads on both sides of the axle. The owner manual says brake linings should always be replaced as complete axle sets. Pads that have been dragging on a stuck caliper are usually glazed or tapered anyway. See our brake pads.
• Rotors, if they are overheated, scored or below minimum thickness. A dragging caliper cooks the rotor on that side. For GS cars with Brembo calipers we carry the Hawk Talon drilled and slotted front rotor set for the 2012 Regal with Brembo calipers. For a complete OE-style refresh, the Brembo OE front disc brake kit for the 2012-2013 Regal pairs UV-coated PVT rotors with Prime ceramic pads; confirm on the product page which caliper version it fits before ordering. Brembo says its PVT pillar-ventilation design raises resistance to thermal cracks by more than 40 percent, and its UV coating is tested for corrosion resistance in a salt spray chamber.
• Hardware and the flexible hose. New abutment clips and slide pin boots cost little. A brake hose that is cracked or swollen can also restrict fluid and hold a caliper on, so inspect it while you are there. See brake hardware kits and brake hoses.
• Brake fluid. Bleed the system after the caliper swap. Use only new fluid of the type marked on the reservoir cap (DOT 3 or DOT 4) from a sealed container, as the manual specifies.

The owner manual also warns that installing brake pads that are wrong for the vehicle can change the balance between the front and rear brakes for the worse. Buy parts made for your exact brake system, not "close enough" parts from a similar GM car.

How hard is the job?

Front caliper replacement on either system is a moderate DIY job for someone with jack stands, a torque wrench and a way to bleed brakes. Remove the wheel, disconnect the brake hose, unbolt the caliper, fit the new one with fresh pads, reconnect, and bleed. Torque every caliper bolt, bracket bolt and the wheel nuts to the values in the factory service manual; do not guess, and replace any bolts the service manual says are one-time-use. The owner manual specifically notes that properly torqued wheel nuts help prevent brake pulsation and that they should be tightened evenly in the proper sequence.

Rear calipers on the Regal take more care because of the Electric Parking Brake. Check the factory service procedure for whether the EPB must be placed in a service or release mode before the rear pistons are retracted. Forcing the piston back against the parking brake mechanism can damage it. If you do not have the tool or procedure, this is the point where a shop visit makes sense.

After the work, pump the pedal until it is firm before moving the car, check the fluid is between MIN and MAX, and bed in the new pads with a series of moderate stops before any hard braking.

Frequently Asked Questions

Is there a recall on 2012 or 2013 Buick Regal brake calipers?

No. NHTSA's recall listings for the 2012 and 2013 Regal cover items such as turn signal lamps, the generator control module, seat height adjusters and rear suspension toe links, but none involve the brakes. Caliper replacement on these cars is normal maintenance.

Do the Regal GS Brembo calipers take the same pads as a regular Regal?

No. The GS four-piston Brembo caliper uses its own pads and rotors. Always confirm whether your car has the Brembo system before ordering pads, rotors or calipers.

Should I replace calipers in pairs?

It is not required, but many techs replace both calipers on an axle when the car is this old, because the second caliper has the same age and fluid history. At minimum, pads must always be replaced as an axle set, as the owner manual states.

What brake fluid does a 2012-2013 Regal use?

The owner manual says the reservoir is filled with either DOT 3 or DOT 4 fluid, as marked on the reservoir cap. Use only the marked type, new from a sealed container. For DOT 4 systems, GM recommends a flush and refill every two years.

Can a stuck caliper damage other parts?

Yes. A dragging caliper overheats the rotor, glazes the pads, and can overheat the wheel bearing and the brake fluid on that corner. That is why a caliper job usually includes pads and often rotors on the same axle.

Why does my Regal squeal only when I first brake in the morning?

The owner manual notes that some driving conditions or climates cause a squeal when the brakes are first or lightly applied, and that this does not mean something is wrong. A constant high-pitched noise while driving is more likely the pad wear indicator.

Sources

1. 2012 Buick Regal Owner Manual (GM) - disc brakes, wear indicators, Electric Parking Brake, axle-set pad replacement, DOT 3/DOT 4 fluid by cap marking, two-year DOT 4 flush, wrong-part and wrong-fluid warnings
2. GM release: Buick Regal GS - four-piston Brembo front calipers, four-wheel disc system, four-channel ABS on the 2012 Regal GS
3. NHTSA recalls: 2012 Buick Regal - no brake-related recalls
4. NHTSA recalls: 2013 Buick Regal - no brake-related recalls
5. Brembo Prime brake rotors - UV coating salt-spray testing, PVT design with over 40 percent more thermal crack resistance