Brake Pads - Rear

Replace rear brake pads on a 2019 Cadillac ATS 2.0L Turbo RWD, including caliper service and proper torque specifications.

Warnings

Tools required

Parts

• Rear brake pad set (inner and outer pads for both sides) × 1 — Use OEM specification or equivalent (Wagner ThermoQuiet, ACDelco)
• Brake hardware kit (clips and shims) × 1 — Often included with premium pad sets

Fluids

• DOT 4 brake fluid — 0.25 qt

Preparation

1. Park vehicle on level, solid ground. Set parking brake (front wheels) and place transmission in Park.
2. Loosen rear wheel lug nuts 1/4 turn while vehicle is on the ground, but do not remove.
3. Locate the brake fluid reservoir under the hood. Remove some fluid with a turkey baster or pump to bring level to the MIN line (prevents overflow when compressing pistons).
4. Raise the rear of the vehicle with a floor jack at the rear differential or manufacturer-specified jacking point.
5. Place jack stands under the rear axle tubes or frame rails per owner's manual specifications.
6. Lower vehicle onto jack stands and verify stability before working underneath.
7. Remove both rear wheels completely and set aside.

Procedure

1. 1

   Inspect brake system condition
   With the wheel removed, visually inspect the brake rotor for excessive wear, scoring, or heat damage. Check the brake hose for cracks, bulging, or fluid leaks. Measure rotor thickness with a micrometer if available; minimum thickness is typically stamped on the rotor hat. If rotors are below minimum thickness or severely damaged, they must be replaced before installing new pads.
2. 2

   Remove caliper slide pin bolts
   Locate the two caliper slide pin bolts on the back side of the caliper. Using a 13mm hex socket, remove the upper and lower slide pin bolts. Keep these bolts as they will be reused. The caliper should now be free to pivot or lift away from the rotor.
   Torque spec

   Caliper Slide Pin Bolts30 Nm (22 lb-ft)
3. 3

   Remove caliper and secure
   Carefully lift the caliper assembly off the rotor and brake pads. Do NOT let the caliper hang by the brake hose. Support it using a wire hanger or bungee cord attached to the suspension or chassis. Leave the brake hose connected unless replacing the caliper.
4. 4

   Remove old brake pads and hardware
   Remove the old inner and outer brake pads from the caliper bracket. Note the orientation and position of any anti-rattle clips or shims. Remove the brake pad hardware clips from the caliper bracket. These clips should be replaced with new ones from the hardware kit.
5. 5

   Clean caliper bracket and slides
   Use a wire brush to clean the caliper bracket pad contact surfaces, removing all rust, debris, and old lubricant. Spray brake cleaner on all surfaces and wipe clean. Inspect the caliper slide pins for corrosion or damage. Clean the slide pin bores in the bracket thoroughly.
6. 6

   Compress caliper piston
   Using a C-clamp or brake caliper piston tool, slowly compress the caliper piston fully into the caliper bore. Place the clamp against the back of the caliper body and a flat piece of metal or old brake pad against the piston face. Compress slowly and watch the brake fluid reservoir; it should not overflow. This step is necessary to make room for the thicker new brake pads.
7. 7

   Install new brake hardware
   Install the new brake pad hardware clips onto the caliper bracket, ensuring they snap firmly into place. These clips should fit snugly and provide smooth surfaces for the brake pad backing plates to slide on.
8. 8

   Lubricate slide pins
   Apply a thin coat of high-temperature silicone brake grease to the caliper slide pins. Do NOT use petroleum-based grease as it will damage rubber components. Apply grease only to the smooth portion of the pins that contact the rubber boots, not the threaded portion.
9. 9

   Install new brake pads
   Install the new inner brake pad (with wear indicator if equipped) into the caliper bracket, ensuring it seats properly in the hardware clips. Install the outer brake pad in the same manner. Verify both pads move freely in the bracket and are positioned correctly with friction material facing the rotor.
10. 10

    Reinstall caliper
    Carefully position the caliper over the new brake pads and align the slide pin bolt holes. Ensure the caliper piston is still fully compressed and the pads are seated correctly. Remove the wire or bungee support.
11. 11

    Install and torque slide pin bolts
    Thread in both caliper slide pin bolts by hand to avoid cross-threading. Tighten both bolts to 30.0 Nm (22 lb-ft) using a torque wrench. Ensure the caliper moves freely on the slide pins after torquing.
    Torque spec

    Caliper Slide Pin Bolts30 Nm (22 lb-ft)
12. 12

    Repeat for opposite side
    Perform steps 1 through 11 on the opposite rear wheel to replace the second set of brake pads. Always replace brake pads in axle sets to maintain balanced braking performance.
13. 13

    Reinstall wheels
    Mount both rear wheels onto the hubs, threading lug nuts on by hand first. Tighten lug nuts in a star pattern snugly with the lug wrench, but do not torque yet while vehicle is on jack stands.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)
14. 14

    Lower vehicle and torque wheels
    Raise the vehicle slightly off the jack stands with the floor jack, remove the jack stands, and carefully lower the vehicle to the ground. Using a torque wrench, torque all rear wheel lug nuts to 140.0 Nm (103 lb-ft) in a star pattern to ensure even seating.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)
15. 15

    Restore brake pedal pressure
    Before moving the vehicle, pump the brake pedal slowly several times until it becomes firm. This extends the caliper pistons to contact the new pads. The pedal should feel normal and firm. If pedal goes to the floor, do not drive the vehicle and recheck all work.
16. 16

    Check and top off brake fluid
    Open the hood and check the brake fluid reservoir. Add DOT 4 brake fluid if necessary to bring the level between MIN and MAX marks. Use only fresh fluid from a sealed container. Wipe away any spills immediately and ensure the cap is sealed properly.

Reassembly

1. Reassembly is covered in the main procedure steps.
2. Ensure all caliper slide pin bolts are torqued to specification with proper brake grease applied.
3. Verify brake pedal is firm before attempting to drive the vehicle.
4. Test brakes at low speed in a safe area before returning to normal driving.

Verification

• Brake pedal should be firm and return to normal height within 2-3 pumps. If pedal is soft or goes to floor, recheck all work immediately.
• Visually inspect all caliper bolts are tight and properly torqued.
• Check for any brake fluid leaks around calipers, hoses, and reservoir.
• Test drive in a safe area at low speed (under 15 mph) and verify brakes engage smoothly without pulling to one side.
• Listen for any unusual noises such as grinding, squealing (light squealing during break-in is normal), or rubbing.
• Verify parking brake still functions properly (it operates on rear brakes).
• After 50-100 miles, re-check wheel lug nut torque and brake fluid level.
• Follow proper brake pad break-in procedure: avoid hard braking for first 200 miles to allow pads to properly seat and cure.

Related trouble codes on this vehicle

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