Rear Disc Brake Service

Difficulty 2/51–2 hrs$80–2202007-2018

Rear disc brake service on a JK is a one-hour-per-side job: pull the caliper, compress the piston, swap pads, and re-torque to 77 ft-lbs on the bracket bolts.

The JK runs disc brakes at all four corners from 2007 on, which is one of the upgrades JK owners take for granted until they go back and try to service drums on a TJ. Rear pads on a JK typically last 50,000 to 80,000 miles depending on tire size, towing, and how much you ride the brake in 4-low. Larger tires and aftermarket bumpers shorten that interval because the unsprung weight and total mass climb without a corresponding brake-system upgrade.

The factory rear pad is semi-metallic. Akebono ProACT ceramics (ACT1274) are the most common upgrade for owners who hate brake dust on the wheels. Ceramics also run cooler in stop-and-go driving but bite slightly softer when cold than semi-metallics. For tow rigs or anyone running 35s and up, PowerStop's Z36 truck-and-tow rear kit (K2798 covers fronts and rears) is the more honest answer than chasing exotic pads on stock-size rotors. You probably don't need slotted-and-drilled rotors for a JK that sees pavement and dirt — they look the part but the drilled holes are a stress riser, not a performance gain.

Inspect the parking brake shoes while you're back there. The JK uses a drum-in-hat parking brake inside the rear rotor, and the shoes get glazed and the adjusters seize on Jeeps that mostly live in 2WD-Auto. If the rotor won't pull off, back off the adjuster through the access slot before forcing it.

Torque the rear caliper guide pin bolts to 22 ft-lbs and the caliper bracket-to-knuckle bolts to 77 ft-lbs. Lug nuts go to 95 ft-lbs in a star pattern. Pump the pedal a dozen times before driving to seat the pad against the rotor — the first stop with new pads should be at low speed in a parking lot, not on the freeway.

Steps

  1. Loosen rear lug nuts, then jack the rear axle and set jack stands under the axle tubes. Pull the wheel.
  2. Remove the two caliper guide pin bolts (13mm head, hex internal on some years) and lift the caliper off. Hang it from a coil with mechanic's wire — do not let it dangle on the hose.
  3. Slide the old pads out of the bracket. Note clip and shim orientation; new pads usually include fresh hardware.
  4. Remove the two caliper bracket bolts (21mm) and pull the bracket off so you can remove the rotor.
  5. Pull the rotor straight off. If it's stuck, back off the parking brake adjuster through the access hole, then strike the rotor hat with a deadblow.
  6. Wire-brush the hub face flat. Any rust ridge here will cause runout and pulsation.
  7. Install the new rotor. Reinstall the caliper bracket — torque to 77 ft-lbs.
  8. Compress the caliper piston with a c-clamp or piston tool. Open the master cylinder cap first and watch the level so it doesn't overflow.
  9. Install new pads with anti-squeal compound on the back of the pad ears, slide the caliper over, and torque guide pin bolts to 22 ft-lbs.
  10. Reinstall the wheel, torque lug nuts to 95 ft-lbs, lower the Jeep, pump the pedal until firm, then bed the pads with 8–10 moderate stops from 35 mph.

Why it works

Trade-offs

Tools required

Parts

PartVendorEst. price
Mopar OEM Rear Pad Set (semi-metallic)Mopar~$65
Akebono ProACT Ceramic Rear PadsAkebono~$55
PowerStop Z36 Truck/Tow Rear Rotor + Pad KitPowerStop~$180
Centric Premium Rear Rotor (each)Centric~$55

Sources

Related

Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.

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