2018-2020 Buick Enclave Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2018-2020 Buick Enclave the front brakes almost always wear out first, because weight shifts forward every time you stop and the front discs do most of the work. The rear pads last longer, but they are the harder job: the Enclave has an Electric Parking Brake that works through the rear brakes, so the rear pistons cannot simply be pushed back. Inspect both axles every time the tires are rotated, and replace pads as complete sets.

How the 2018-2020 Enclave Brake System Is Laid Out

The second-generation Enclave that arrived for 2018 uses disc brakes at all four corners, a hydraulic system filled with GM-approved DOT 3 fluid, and an Electric Parking Brake (EPB) in place of a foot pedal. GM's owner manual for this generation describes the EPB switch, the PARK light that flashes and then stays on once the brake is fully applied, and a separate Service Parking Brake light that signals a fault.

What matters for brake service is how the two axles split the job:

• Front brakes handle the bulk of everyday stopping. Under braking the Enclave's weight pitches forward, loading the front tires and asking more of the front pads and rotors. The front rotors are the larger, ventilated pair so they can shed that heat.
• Rear brakes do a smaller share of the service braking, but they also serve as the parking brake. The EPB applies the rear brakes when you press the switch, when the system runs its own periodic self-check, and when Adaptive Cruise Control brings the vehicle to a stop and holds it.

Because the rears double as the parking brake, the manual warns that driving with the parking brake applied can overheat the brake system and cause premature wear or damage, and it tells owners to avoid rapid acceleration with the EPB applied in order to preserve parking brake lining life.

What Wears First: Front vs Rear

The pattern is not guaranteed on every vehicle. A rear caliper with a sticking slide pin or piston, or a parking brake that is not fully releasing, can wear the rear pads faster than the fronts. That is why the owner manual tells you to inspect the brake pads whenever the tires are rotated, which GM schedules every 7,500 miles (12 000 km) on this Enclave. Checking both axles at every rotation catches an uneven rear before it ruins a rotor.

Symptoms and How to Tell Which End Needs Work

• High-pitched squeal while driving that goes away when you brake firmly. GM states that the Enclave's disc brake pads have built-in wear indicators that make exactly this sound when the pads are worn. Pull the wheels and look at both axles; the squeal usually starts at the front.
• Steering wheel shake when braking. Points to the front rotors. GM specifically warns that improperly tightened wheel nuts can lead to brake pulsation and rotor damage, so correct lug torque is part of the repair, not an afterthought.
• Pulsation felt in the seat or the pedal while the steering wheel stays steady. More often a rear rotor problem.
• Flashing PARK light or a lit Service Parking Brake light. The EPB is only partly applied or has a fault. The manual says not to drive with the PARK light flashing, and to have the vehicle serviced.
• Falling brake fluid level. GM lists only two causes: normal brake lining wear, or a leak in the hydraulic system. Do not top the reservoir off because the pads are worn, or it will overflow when new pads push the pistons back.
• Pedal travel increasing, or the pedal not returning to its normal height. GM lists this as a sign that brake service is required.

The Fix: Which Parts to Buy for Each Axle

Front brake job

Most Enclaves need front pads first. A quality ceramic pad keeps dust down and stays quiet on a heavy three-row crossover, and our Bosch front ceramic brake pads for the 2018-2020 Enclave are a direct fit. If the rotors are scored, below the minimum thickness cast into the hat, or causing pulsation, replace them as a pair from our brake rotors collection. Fresh abutment clips from a brake hardware kit let the new pads slide freely and stay quiet.

Rear brake job

Rear pads and rotors are ordinary parts; the procedure is what is different. Brake & Front End, the industry trade publication, notes that on GM models with an electronic parking brake it may be necessary to disengage the parking brake during a rear pad or rotor job, and that the preferred method is a scan tool. Its broader EPB guide is blunt: a brake job on a vehicle with an electronic parking brake needs a scan tool with the proper software to retract the calipers, and unapproved shortcuts will set malfunction codes and can damage the unit. Matching rear pads are in our ceramic brake pads collection.

If a rear caliper is seized or leaking, replacements are in our brake calipers collection. Whatever you replace, GM's rule applies: always replace brake system parts with new, approved replacement parts, and replace brake pads as complete sets.

What to Replace at the Same Time

• Rotors when they are below minimum thickness, grooved, cracked or causing pulsation. Always in axle pairs.
• Hardware: abutment clips, shims and slide pin boots, with the slide pins cleaned and lubricated.
• Brake fluid: GM calls for replacing it every five years on this Enclave, using only GM-approved DOT 3 from a clean, sealed container. If yours is due, pair the flush with the pad job.
• Brake hoses if they are cracked, chafed or swollen. See our brake hoses.

How Hard Is the Job?

The fronts are a normal driveway job for someone with jack stands and a torque wrench. Torque the caliper and bracket bolts to the values in the factory service manual, then tighten the wheel nuts in a crisscross sequence to GM's published wheel nut torque of 140 lb ft (190 Nm). Bed the new pads in gently: GM warns that hard stops before the linings are broken in mean premature wear and earlier replacement.

The rears are a step up. You need a way to put the EPB into service mode, most reliably a scan tool that supports GM parking brake functions, and then to exit service mode and confirm the PARK light applies and releases normally before the vehicle goes back on the road. If you do not have that capability, paying a shop for the rear axle is money well spent. It is also worth checking your own vehicle's recall status: NHTSA's database shows no brake-system recalls for the 2018, 2019 or 2020 Enclave, but only a VIN lookup confirms what applies to yours.

Frequently Asked Questions

Do the front or rear brakes wear out first on a 2018-2020 Buick Enclave?

The fronts, in normal driving, because they do most of the stopping work. If your rears are wearing faster, look for a sticking caliper, seized slide pins or a parking brake that is not releasing completely.

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

Not before the Electric Parking Brake is placed in service mode. The rear brakes are what the EPB applies, and forcing the pistons back can damage the parking brake mechanism and set fault codes. A scan tool with GM parking brake functions is the preferred method.

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

Only when both are actually worn. Pads are replaced as complete sets per axle. Many owners do two front jobs for every rear job, so measure rather than guess.

What brake fluid does the 2018-2020 Enclave use?

GM-approved DOT 3 brake fluid, as marked on the master cylinder reservoir cap. GM recommends replacing the fluid every five years, because it absorbs water over time and that increases stopping distance.

Why does my Enclave squeal only when I am not braking?

That is the sound of the built-in pad wear indicators. GM notes the sound can come and go or be heard constantly while moving, except when the brake pedal is pressed firmly. Have the pads replaced soon.

Are there brake recalls on the 2018-2020 Enclave?

NHTSA's recall database lists no brake-system recalls for these model years. Run your VIN on nhtsa.gov to confirm that nothing applies to your specific vehicle.

Sources

1. 2019 Buick Enclave Owner Manual (General Motors) - DOT 3 fluid, five-year fluid replacement, pad wear indicators, EPB operation and warnings, 7,500-mile rotation with pad inspection, 140 lb ft wheel nut torque
2. 2020 Buick Enclave Owner Manual (General Motors) - confirms the same fluid spec, five-year interval, wear indicators and wheel nut torque carry through 2020
3. NHTSA recall lookup, Buick Enclave - no brake-system recalls listed for the 2018-2020 Enclave
4. Brake & Front End: GM Electronic Parking Brake Procedures - disengaging the EPB for GM rear pad and rotor work, with a scan tool as the preferred method
5. Brake & Front End: Electronic Parking Brake Diagnostics - a scan tool with the proper software is needed to retract EPB calipers; shortcuts set codes and can damage the unit