Rear drum brakes do only about 30% of the XJ's stopping, which is exactly why they get ignored until the parking brake won't hold or you hear metal-on-metal — this is how to service them properly and get the self-adjuster working again.
The XJ runs rear drums for its entire 1984–2001 run, most commonly 9" x 2.5" units on the Chrysler 8.25 and Dana 35 axles, with 10" drums on early Dana 44 trucks. They're not glamorous and they're fussier than the front discs — a drum brake is a fistful of little springs, a self-adjuster that seizes if you look at it wrong, and a parking-brake lever buried in the middle. None of it is beyond you. The trick is to work one side at a time, photograph everything before you pull it apart, and use the still-assembled side as your reference.
You'd do this job when the parking brake stops holding on a grade, when you hear a scrape or grind from the rear, when the pedal sits low because the self-adjusters have stopped taking up slack, or because nobody has been in there in 100,000 miles and the hardware has gone to rust. Shoes are condemned when the friction material is down to about 1/16" (1.5mm) or near the rivet heads. If you've got fluid weeping at the back of the drum, the wheel cylinder is leaking and gets replaced — brake fluid on the shoes ruins them, so plan to do both at once.
A few XJ-specific truths before you start. The factory return and hold-down springs lose tension after two decades of heat cycling, and weak springs are the number-one reason these self-adjusters quit working — buy the hardware kit and replace the springs whether they look bad or not, it's $18. Cheap aftermarket backing-plate sets (the Dorman 924-665 in particular) are known to fit poorly and prevent the cylinder or shoes from seating; if you're only doing shoes and hardware, leave the backing plate alone. And the drums themselves rust-weld to the axle flange on any XJ that's seen moisture — there's a documented way off, covered below, that doesn't involve beating on the axle.
This guide replaces shoes, hardware, and (if needed) wheel cylinders. Brake work is safety-critical: if you are not confident the rear brakes will hold afterward, have the work checked before you drive in traffic.
Steps
Chock the front wheels and break the rear lug nuts loose on the ground. Crack each lug a quarter turn before lifting. With the rear in the air the parking brake won't hold the axle still, so do this first.
Raise the rear axle and set it on jack stands. Place the stands under the axle tube near each spring perch, then lower the jack until the axle rests on the stands. Never work behind a wheel supported only by a jack.
Release the parking brake fully and remove the rear wheels. A set parking brake will keep the shoes clamped to the drum and fight you when you try to pull it.
Pull the brake drum. Most XJ drums are retained only by a couple of push-on spring nuts on the wheel studs — cut or pry those off and discard them; they're a factory assembly aid, not needed for reassembly. If the drum is rust-welded to the flange and won't budge, do not pry against the axle. First back the shoes off: pop the rubber access plug from the slot in the backing plate and use a brake spoon or screwdriver to spin the star wheel so the shoes retract. Then thread two bolts into the drum's threaded puller holes (8mm x 1.25 on most XJ drums) and tighten them in alternation to walk the drum off. A few hits with a dead-blow hammer on the drum's outer face — between the studs, never on the studs — breaks the rust bond on stubborn ones.
Stop and photograph the assembly from straight on. Both shoes, both return springs, the adjuster cable routing, the self-adjuster lever, the hold-down pins, and the parking-brake strut. This photo is worth more than any diagram when you reassemble. Then do the same to the opposite side before you disturb it — the two sides are mirror images, so a good reference of the side you haven't touched yet saves you.
Knock the dust loose with brake cleaner, not your lungs. Set a drain pan under the backing plate and flush the assembly with brake parts cleaner. Old brake dust may contain material you don't want to breathe — wet it down, don't blow it out with compressed air.
Clamp the wheel cylinder pistons. Slip a small spring clamp or a purpose-made cylinder clamp over the cylinder so the pistons can't pop out and dump fluid while the shoes are off.
Remove the return springs from the anchor pin. Use the hooked end of the drum brake spring tool to lever the primary and secondary return springs off the anchor pin at the top. They're under tension — keep your face out of the line of travel.
Remove the hold-down springs. Push in on each hold-down cap, turn it 90°, and release — the pin backs out the rear of the backing plate. A dedicated hold-down tool makes this trivial; needle-nose pliers also work.
Lift out the self-adjuster. Remove the adjuster lever, the adjuster cable and its guide, then the star-wheel adjuster screw and its spring. Lay them out in the order they came off. This cluster is what fails most often — clean every piece, and if the star wheel won't spin freely with light finger pressure after cleaning, replace it from the hardware kit.
Free the shoes and the parking-brake hardware. Remove the parking-brake strut and its spring, spread the shoes apart, and lift the shoe assembly off the backing plate. Disconnect the parking-brake cable from the lever, then move the lever to the new secondary (rear) shoe — it's held by a washer and a U-clip; use the new clip from the kit, not the old one.
Inspect and replace the wheel cylinder if it's weeping. Peel back the rubber boot at each end — any wetness or crust behind the boot means it's leaking and the cylinder is done. To replace: crack the brake line fitting at the back of the cylinder with a line wrench (a regular open-end wrench rounds these old fittings), remove the two mounting bolts behind the backing plate, swap the cylinder, and torque the mounting bolts to 90 in-lb (7.5 ft-lb) — they thread into thin stamped steel and will strip if you treat them like chassis bolts. Snug the line fitting; you'll be bleeding it anyway.
Clean and lubricate the backing plate. Wire-brush the six raised shoe-contact pads on the backing plate and the anchor pin, then apply a thin film of high-temp brake lubricant to each pad, the anchor pin, and the adjuster threads. Grease only the metal-to-metal contact points — never the friction surface of the shoe or the inside of the drum.
Assemble the new shoes off the vehicle first if you can. Connect the primary (front) and secondary (rear) shoes with the new star-wheel adjuster at the bottom and the new adjuster spring. Note that the adjuster star wheel goes toward the rear of the vehicle on the XJ. Getting the shoe pair pre-linked makes mounting far less of a wrestling match.
Mount the shoe assembly to the backing plate. Seat each shoe on its contact pads, install the new hold-down pins, springs, and caps (push in, turn 90° to lock), then fit the parking-brake strut and spring between the shoes.
Install the self-adjuster and return springs. Route the new adjuster cable over its guide and onto the anchor pin, hook on the adjuster lever, then install both return springs onto the anchor pin with the spring tool. Pull the adjuster lever by hand and confirm it ratchets the star wheel a notch — if it doesn't, the cable is routed wrong or the spring is on the wrong shoe. Compare to your photo.
Remove the cylinder clamp and pre-set the adjustment. Spin the star wheel out until the shoes barely let the drum slide on with light drag. Too loose and the pedal will be low until the self-adjuster catches up; too tight and the drum won't go on.
Fit the drum and fine-tune through the backing-plate slot. With the drum on and the wheel chocked, rotate the drum by hand and turn the star wheel through the access slot until you feel a slight, even drag — the drum should turn with light resistance, not lock up and not spin completely free. Reinstall the rubber access plug.
Set the self-adjuster with the parking brake. Apply and release the parking brake firmly several times — on a properly assembled XJ drum this cycles the self-adjuster and centers the shoes. Recheck the drag and repeat the star-wheel tweak if needed.
Repeat the entire process on the other side. Do one side fully, then the second — never both at once, so the assembled side is always your reference.
Bleed the rear brakes if you opened a line. If you replaced a wheel cylinder, bleed that wheel (and ideally the whole system) using the two-person pedal method, starting at the wheel farthest from the master cylinder. Top off with DOT 3 (factory spec) or DOT 4 — never add DOT 5 silicone to a DOT 3/4 system.
Mount the wheels and torque the lug nuts to 95 ft-lb in a star pattern. Factory spec runs 80–110 ft-lb across model years; 95 ft-lb is a safe middle. Lower the truck onto the ground for the final torque.
Pump the pedal, then test at low speed before traffic. Pump the brake pedal until it comes up firm and high — the first few strokes take up the gap to the new shoes. Then do several gentle stops from low speed in a safe area, confirm the truck stops straight, and verify the parking brake holds on a grade before you drive normally. New shoes need a few hundred miles of moderate use to fully seat against the drum.
Why it works
A complete rear drum service — shoes, hardware, and both wheel cylinders — runs well under $160 in parts and restores the parking brake and a firm pedal in an afternoon.
Replacing the springs and self-adjuster while you're in there fixes the low-pedal, won't-self-adjust problem at its root instead of chasing it later.
It's a self-contained skill: once you've done one XJ drum, every drum-braked Jeep on the trail makes sense, and you can talk someone else through theirs.
Trade-offs
Drum hardware is fiddly and unforgiving — a misrouted adjuster cable or a spring on the wrong shoe means the self-adjuster won't work, and you'll be back in there. Photograph everything and work one side at a time.
Some aftermarket parts fit poorly. Stick with name-brand shoes, hardware, and cylinders (Centric, ACDelco, Carlson, Raybestos) and avoid the cheapest no-name backing-plate kits, which are documented to keep the cylinder and shoes from seating.
If you live where it's wet and the drums are rust-welded on, plan extra time and have the puller-bolt trick ready before you start — prying on the axle flange will damage it.
If you're regularly carrying weight, towing, or running larger tires, the rear drums are the weakest part of the XJ brake system. A rear disc conversion (using ZJ or WJ Grand Cherokee parts) is the real upgrade once you've outgrown the drums — but for a stock-to-mild rig, fresh drums stop fine.
Tools required
Floor jack and two jack stands
Wheel chocks
19mm socket or impact for lug nuts
Drum brake spring tool (combination spoon/retainer tool)
Brake hold-down spring tool or needle-nose pliers
8mm or 5/16" socket and short extension (wheel cylinder bolts)
Line wrench (10mm / 3/8") if replacing the wheel cylinder
Torque wrench (inch-pound and foot-pound)
Brake spoon or flat screwdriver (star-wheel adjustment)
Brake parts cleaner — at least two cans
High-temp brake lubricant (for backing-plate pads and adjuster)
Drain pan and shop rags
Phone camera (photograph the assembly before you touch it)
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.