1990-1999 Jeep Cherokee Brake Caliper Problems and Replacement

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 1990-1999 Jeep Cherokee (XJ), front brake caliper problems almost always come down to one of three things: a sticking piston, seized or worn slide pins and bushings, or a leaking piston seal. The front caliper on these years is a simple single-piston floating design, so it is one of the easier brake jobs on the truck, and it is usually smart to replace or rebuild both sides together along with fresh pads.

How the Front Caliper Works on the 1990-1999 Cherokee

From 1990 on, the XJ switched to a different front caliper than the 1984-1989 trucks, and that later caliper carried through to the end of production in 2001. It is a floating caliper with one large phenolic (composite) piston - remanufactured units for these years list a piston diameter of 2.597 inches. When you press the pedal, fluid pushes the piston out against the inboard pad, and the caliper body slides inward on its pins to pull the outboard pad against the rotor.

That sliding action is the key to how this caliper wears. The caliper rides on four caliper pins per truck (two per side), each running through a rubber pin boot (bushing) and a sleeve, with an anti-rattle support spring keeping the assembly quiet. If the pins cannot slide freely, the caliper stops centering itself and one pad does most of the work.

The same caliper design is shared across a lot of Jeeps of the era: the 1990-1992 Comanche, 1990 Wagoneer, 1993-1998 Grand Cherokee, Wrangler YJ and TJ. Calipers are side-specific (left and right are different parts), so order them as a pair. The front rotor on 1990-1999 trucks is a vented 11.02-inch (280 mm) disc, while the rear of every XJ uses drum brakes - 9 x 2-1/2 inch drums on the Dana 35 axle for 1990-2001 - so the front calipers do most of the stopping.

Symptoms of a Bad Caliper on a Cherokee XJ

• Pulling to one side under braking. A caliper that is sticking on one side, or not applying fully on the other, makes the Jeep dart toward the side that is gripping harder.
• Pulling or dragging when you are not braking. A piston that will not retract, or pins that are seized, keep a pad pressed on the rotor. You may notice lost coasting, worse fuel economy and a burning smell after a drive.
• One wheel much hotter than the other. After a short drive with light braking, carefully compare the wheels by holding a hand near (not on) each hub. A dragging caliper runs noticeably hotter.
• Uneven pad wear. An inboard pad worn to the backing plate with a healthy outboard pad (or the reverse), or a pad worn into a taper, points to frozen slide pins.
• Brake fluid on the inside of the wheel or tire. A wet caliper, a torn piston boot or a damp hose connection means a leak. Stop driving it until it is fixed.
• Soft or sinking pedal and a dropping fluid level. With pads that still have plenty of material, a falling reservoir level means fluid is going somewhere.
• Clunk or rattle over bumps. Worn pin bushings or a missing anti-rattle spring let the caliper knock in its mount.

What Causes XJ Caliper Problems

Age and corrosion. Even the newest of these trucks is more than 25 years old. Road salt and moisture get under the pin boots, and the pins and sleeves rust or the grease hardens until the caliper can no longer float.

Torn piston boot. Once the dust boot around the piston splits, dirt and water reach the piston and bore. Phenolic pistons do not rust, but they can chip or crack, and debris in the bore makes the piston stick.

Old, wet brake fluid. Glycol-based brake fluid absorbs water over time. Federal standard FMVSS 116 requires fresh DOT 3 fluid to boil no lower than 401 F, but the wet test (fluid with absorbed water) only requires 284 F. Water also corrodes the inside of the caliper, which is why a truck that has never had its fluid flushed tends to have sticky calipers. Use the fluid type printed on your master cylinder cap.

Collapsed flex hose. A rubber brake hose can deteriorate inside and act like a one-way valve, holding pressure on the caliper after you release the pedal. If a caliper drags but the piston pushes back easily once the hose is opened, suspect the hose.

Worn-out pads. Running pads to the backing plate pushes the piston far out of its bore into the dirty section that normally sits behind the boot, and it often sticks there.

Replace, Rebuild or Just Service the Pins?

If the only problem is uneven pad wear and the pins are simply dry, cleaning the pins and sleeves, installing new boots and lubricating with high-temperature silicone brake grease may be all it needs. A hardware kit is inexpensive and worth doing at every pad change - see our brake hardware kits.

If the piston is sticking, the boot is torn, or the caliper is leaking, you have two options. A caliper repair kit replaces the piston, seal and boot, but only works if the bore is clean and free of pitting. For most owners, a complete replacement caliper is the better use of time, since it arrives with a good bore, new seal and new boot. Browse replacement brake calipers, and replace both front calipers together so braking stays even side to side.

What to Replace at the Same Time

• Front pads. A leaking or dragging caliper contaminates or glazes the pads; do not reuse them. For 1997-1999 Cherokees with the 2.5L and 82 mm high rotors we carry EBC Yellowstuff front brake pads (DP41255R), and for 1990-1991 2.5L 4WD trucks, EBC Greenstuff 6000 front brake pads (DP61022). More options are in our brake pads collection.
• Rotors. A dragging caliper overheats the rotor, often leaving it warped or discolored. If the rotor is scored, below the minimum thickness stamped on the disc, or causes a pulsing pedal, replace it - see brake rotors.
• Front brake hoses. On a truck this old, new brake hoses are cheap insurance and eliminate the collapsed-hose problem. Use new copper sealing washers at the banjo fitting.
• Brake fluid. Flush the whole system, not just the fronts, so the new calipers are not filled with old, wet fluid.

How Hard Is the Job?

This is a beginner-to-intermediate job that most owners can do in an afternoon with basic hand tools, a C-clamp or piston tool, a flare-nut wrench and a way to bleed the brakes. The general order is: loosen the lugs, lift and support the Jeep on stands, remove the wheel, cap off the hose to limit fluid loss, remove the banjo bolt, remove the caliper pins, lift the caliper off, then install new pads and hardware and reverse the process.

Torque the caliper pins, banjo bolt and lug nuts to the values in the factory service manual - do not guess. Bleed each caliper at its bleeder screw in the sequence the manual specifies until no air comes out. Pump the pedal to seat the pistons before moving the vehicle, then bed in the new pads with a series of moderate stops. Recheck for leaks and verify the fluid level after the first drive.

Frequently Asked Questions

Are the front calipers the same on all 1990-1999 Cherokees?

Yes. The same floating single-piston front caliper was used on the XJ from 1990 through 2001, with separate left and right parts. The 1984-1989 trucks used a different caliper, so make sure you order for the correct year.

Will a Grand Cherokee or Wrangler caliper fit my XJ?

The same caliper is listed for the 1993-1998 Grand Cherokee, Wrangler YJ and TJ, and 1990-1992 Comanche, among others. Always confirm fitment for your exact year and side before ordering.

Should I replace both front calipers or just the bad one?

Replace them as a pair. A new caliper on one side and a tired, slow caliper on the other can cause a pull, and the old one is usually not far behind.

Why does my Cherokee pull left or right only when braking?

The most common causes are a sticking caliper piston, seized slide pins, a collapsed brake hose, or contaminated pads on one side. Check pad wear and wheel temperature side to side to find which corner is the problem.

Can I just rebuild my original XJ calipers?

You can, with a kit that includes a new piston, seal and boot, but only if the bore is clean and unpitted. On calipers this old, a replacement caliper is usually faster and more reliable.

Does the XJ have rear calipers?

No. The Cherokee XJ uses drum brakes on the rear axle, so rear brake work involves shoes, drums, wheel cylinders and hardware rather than calipers. See our brake shoes.

Sources

1. Crown Automotive - Cherokee XJ front brake parts - 1990-2001 XJ caliper is side-specific, uses four caliper pins, pin boots and sleeves, anti-rattle support springs, 3/8-24 bleeder, 280 mm vented rotor, single-piston repair kit
2. Cardone - reman front caliper for 1990-2001 Jeep Cherokee - floating single-piston caliper, 2.597 in phenolic piston, 3/8x24 bleeder, shared with Comanche, Wrangler YJ/TJ and 1993-1998 Grand Cherokee
3. Cardone - opposite-side reman caliper for 1990-2001 Cherokee - matching opposite-side caliper with the same piston size and fitment list
4. Quadratec - Cherokee XJ rear brakes - XJ uses rear drum brakes; 9 x 2-1/2 in drums on 1990-2001 Dana 35 axles
5. 49 CFR 571.116 (FMVSS 116) via Cornell LII - DOT 3 minimum dry boiling point 205 C / 401 F and wet boiling point 140 C / 284 F