2019-2020 Jeep Gladiator Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

If the parking brake on your Jeep Gladiator (JT) will not hold on a grade, drags after you release it, or the lever pulls up too far, the cause is almost always in the rear: worn or out-of-adjustment parking brake shoes inside the rear rotors, or a stretched or sticking cable. The fix is usually an adjustment at the rear wheels, not a new lever. This guide explains how the Gladiator's parking brake works, how to diagnose it, and how it is adjusted.

How the Gladiator Parking Brake Works

The Gladiator is a four-wheel disc brake truck. Jeep's 2020 Gladiator specifications list a vented front rotor with a twin-piston floating caliper and a vented rear rotor, 13.6 x .86 in (345 x 22 mm), with a single-piston floating caliper. That rear caliper is a plain hydraulic caliper; it is not what holds the truck when it is parked.

The parking brake is a separate, mechanical system. A hand lever in the center console, behind the gear selector, pulls cables that run back to each rear wheel. At the wheel, the cable operates a small pair of brake shoes that sit inside the hat (the center section) of the rear rotor. The inside of the rotor hat is machined as a small drum, which is why this layout is called drum-in-hat. The shoes are set by a star-wheel adjuster, and that clearance should be set by hand whenever shoes or rotors are replaced.

Because the parking shoes only touch the drum when you pull the lever, they wear very slowly. Most problems come from adjustment, corrosion, or the cable rather than from worn-out lining.

Symptoms and What They Point To

The owner's manual is specific about the warning light. With the ignition on, the Brake Warning Light comes on whenever the parking brake is applied, and it flashes if the parking brake is applied with an automatic transmission in gear. Jeep notes the light only shows that the brake is applied, not how hard it is applied, so a lit light does not prove the brake is holding. If the light stays on after the lever is released and the master cylinder is full, the manual treats it as a possible hydraulic or brake booster malfunction and says to have the system serviced immediately.

Common Causes on Off-Road and Daily-Driven Gladiators

• No adjustment after a rear brake job. When the rear rotors are replaced, the new rotor hat is a fresh, full-size drum. If the shoes are not adjusted out to meet it, the lever has to travel much farther before anything holds.
• Cable stretch. Parking brake cables stretch over time, which adds slack and increases lever travel. This is normal wear, and it is corrected at the cable adjuster only after the shoes are set correctly.
• Corrosion and moisture. Water crossings, mud and road salt get behind the rotor. Shoes can swell with moisture and cause drag, and the actuator and adjuster can rust solid. A parking brake that is never used is more likely to seize than one used every day.
• Contamination. A leaking axle seal or grease on the shoes will kill holding power. Contaminated lining cannot be cleaned back to spec; the shoes get replaced and the leak gets fixed first.
• Driving with the lever partly up. Jeep warns to make sure the parking brake is fully released before driving. Even a few miles with the shoes dragging can glaze the lining and heat the rear rotor.

How the Parking Brake Is Adjusted

The order matters: shoes first, cable second. Adjusting the cable to make up for loose shoes just pulls the lever tighter while the shoes still sit far from the drum.

1. Chock the front wheels, release the parking brake fully, and raise and support the rear of the truck. Remove the rear wheel.
2. Find the adjusting access. On drum-in-hat designs the shoes are adjusted by turning a star wheel, reached through an adjusting slot or access hole with a brake adjusting spoon.
3. Turn the rotor by hand and turn the star wheel until the shoes just begin to drag on the drum.
4. Back the star wheel off until the rotor turns freely with no contact. If your service information specifies a number of adjuster teeth or a shoe-to-drum clearance measured with a drum gauge, follow that exactly. Brake trade guidance is blunt on this point: if the procedure says back off a set number of teeth, use that number, not one more or one less, because clearance specs exist to prevent drag and noise when shoes expand.
5. Repeat on the other side, reinstall the wheels and torque the lug nuts to the value in the owner's manual or factory service manual.
6. Only now check lever travel. If it is still excessive, take up cable slack at the cable adjuster until the brake holds firmly within normal lever travel and both rear wheels still spin freely with the lever down.

If the rotor will not come off the hub because the shoes have grown into a rust lip, back the adjuster off first through the access hole; forcing the rotor off can break the shoes or hardware.

After new shoes or rotors, the shoes need to seat against the drum before they hold at full strength. Follow the break-in procedure in the shoe maker's instructions or the factory service manual rather than guessing speeds and number of applications.

What to Replace at the Same Time

The parking shoes live inside the rear rotor, so the rear brakes all come apart together. That makes it smart to look at everything back there at once:

• Rear pads. If the rear pads are near the wear limit, replace them while the caliper is off. For a Gladiator that tows or carries weight, the EBC Extra Duty rear brake pads for the Gladiator are built for heavier use, the EBC Yellowstuff rear pads are a high-friction street and tow compound, and the Hawk LTS rear brake pads for the Gladiator JT are designed for light trucks and SUVs.
• Rear rotors. Check both faces for the service limit and check the inside of the hat. A drum surface that is badly scored, rusted or out of round will not give the shoes a good surface. See our brake rotors selection.
• Shoe hardware. Springs and hold-downs get tired and rusty. Replacing the brake hardware kit with the shoes is inexpensive insurance.
• Front brakes. If the front pads and rotors are due too, doing both axles together keeps the brake balance even. Front rotor options for the Gladiator include the EBC GD Sport slotted front rotors.

Jeep's maintenance schedule calls for inspecting the brake pads, shoes, rotors, drums, hoses and park brake at every oil change interval, so a shop visit is a good time to have the parking brake checked before it becomes a problem.

How Hard Is the Job?

Adjusting the parking brake on a Gladiator is a moderate driveway job if you have a jack, stands and a brake spoon. The fiddly part is feeling for the star wheel through the access hole, and on a truck that sees mud or salt the adjuster may be seized. Replacing the parking shoes is a step up: the rear caliper and rotor come off, and the shoe springs and hold-downs take patience. If the rear rotor is rusted to the hub or the shoes have broken apart, expect the job to take longer. Anyone uncomfortable working on brakes should leave it to a shop.

Before any parts are ordered, it is worth checking for open recalls. As of this writing, NHTSA's recall list for the 2020 Gladiator includes campaigns for the driveshaft, clutch, seat belts, rear camera and instrument panel, but none for the service or parking brakes. Run your own VIN at nhtsa.gov to confirm for your truck.

Frequently Asked Questions

Does the Jeep Gladiator have an electronic parking brake?

No. The Gladiator uses a hand lever in the center console, behind the gear selector, that operates cables to shoes in the rear rotors. You pull it up firmly to apply it and push the center button to release it.

Why does my Gladiator parking brake not hold after new rear rotors?

The parking shoes almost certainly were not adjusted out to the new rotor hat. Set the shoes with the star-wheel adjuster first, then check the cable. Also make sure no grease or brake cleaner residue got on the shoe lining during the job.

Can I just tighten the cable instead of adjusting the shoes?

You can shorten lever travel that way, but the shoes stay loose and the cable ends up doing work it was not meant to do. The correct order is shoes first, then cable.

Why is the brake light on when the parking brake is off?

The Gladiator's Brake Warning Light also monitors brake fluid level and hydraulic and booster faults. If it stays on with the lever fully down and the fluid full, Jeep says to have the brake system serviced right away.

Should I use the parking brake if I have an automatic?

Yes. Jeep's manual says never to use PARK as a substitute for the parking brake, and to apply the parking brake before shifting into PARK on a hill so the transmission lock is not carrying the load. Regular use also keeps the cables and shoes from seizing.

Sources

1. 2020 Jeep Gladiator Owner's Manual (Mopar) - parking brake lever location and operation, Brake Warning Light behavior, PARK vs parking brake warnings, maintenance schedule inspection of shoes and park brake
2. 2020 Jeep Gladiator Specifications (FCA US media) - four-wheel disc brakes, rear 13.6 x .86 in vented rotor with single-piston floating caliper
3. Brake and Front End: Adjusting Parking Brakes - drum-in-hat star wheel adjustment through the hat slot, back-off procedure, clearance specs, cable stretch
4. NHTSA recalls data, 2020 Jeep Gladiator - list of recall campaigns, none for brakes