2003-2006 Ford Expedition Brake Caliper Problems and Replacement

By Core Brake Parts Tech Team — Circleville, OH warehouse

Caliper trouble on a 2003-2006 Ford Expedition usually shows up as a pull to one side, one wheel running hot, or pads that wear unevenly on one corner. Most of the time the cause is a seized slide pin or a sticking piston rather than a dramatic failure, and the fix is a pair of calipers with fresh hardware and lubricant, plus pads and often rotors on that axle.

This guide covers how the brakes on this generation of Expedition are laid out, how to tell a bad caliper from other brake problems, what to replace together, and how involved the job is for a driveway mechanic.

How the Brakes Work on the 2003-2006 Expedition

This generation of Expedition uses disc brakes at all four wheels. Up front, each wheel has a floating caliper with two pistons. Cardone's remanufactured caliper listed for the 2003-2006 Expedition and Lincoln Navigator is a two-piston floating design with steel pistons, a cast iron body and a separate mounting bracket. A floating caliper does not have pistons on both sides of the rotor; the pistons push the inner pad, and the caliper body slides on its pins to pull the outer pad into the rotor. That sliding action is why the pins matter so much on these trucks.

At the rear, Ford's parts catalog for the 2005 Expedition lists a separate left and right caliper, a caliper bracket for each side, the rotor, and a brake shoe and lining kit. The shoes are the parking brake: this is a drum-in-hat design, where small shoes expand against the inside of the rear rotor's hat section when you set the parking brake. So a rear brake job on this truck can involve both pads and parking brake shoes.

Cardone also lists more than one caliper design across this model span, including one listed for the 2003 model year only with a different piston size. Two calipers that look alike can have different bores, so match the replacement to your exact year and position rather than to a photo.

Symptoms of a Bad Caliper on This Expedition

• Pull under braking. If one front caliper is not applying or releasing properly, the truck pulls toward one side when you brake.
• One wheel hotter or dirtier than the others. A caliper that does not release keeps the pads dragging. After a drive, that wheel is noticeably hotter and may carry more brake dust. A burning smell after a highway run points the same way.
• Uneven pad wear. Brake and Front End's tech guidance lists uneven wear between the two pads, or one pad wearing much faster than the other, as the classic sign of a slider caliper that is not free to move. On a front Expedition caliper that usually means the inner pad is worn far thinner than the outer.
• Noise. ADVICS notes that pad noise and excessive pad wear are symptoms of a sticking slide pin.
• Fluid on the inside of the wheel or a dropping reservoir. A torn piston seal leaks. Ford's own guidance is that a brake fluid level that keeps going down means the brake system needs service.
• Soft pedal after a leak. Lost fluid or air in the system shows up as a pedal that sinks further than normal.

What Causes Caliper Problems on a Truck This Age

These trucks are now roughly two decades old, and the common failures are age and corrosion rather than a design defect. A check of NHTSA's recall data for the 2003 and 2004 Expedition turned up no brake caliper recalls; the entries listed there involve aftermarket lamps and running boards. Caliper problems on these trucks are a wear-and-maintenance issue.

• Seized or dry slide pins. ADVICS explains that pins rust once the grease is gone, and heat and friction damage the pin boot and sleeve. Once the pin binds, the caliper cannot float and the pads drag or wear on one side.
• Bent pins, worn slides or damaged brackets. Brake and Front End lists bent or binding mounting pins, worn slides, bent or damaged brackets, swollen or hardened guide seals and lack of lubrication as the reasons a slider caliper stops moving freely.
• Corroded pistons and torn dust boots. Once the dust boot splits, water and road salt reach the piston. Rust on the piston face and in the bore makes the piston stick, and it can eventually damage the seal and start a leak.
• Old, dark brake fluid. Brake fluid picks up moisture over time, which promotes internal corrosion. Ford recommends having the system checked if the fluid is dark.
• Rear parking brake neglect. On the drum-in-hat rear setup, seized parking brake hardware can drag the shoes against the rotor hat and mimic a stuck rear caliper. Check both before buying parts.

How to Confirm It Is the Caliper

1. After a drive, carefully compare how warm each wheel is by holding your hand near (not on) the wheel. One corner much hotter than the others points to a dragging caliper or parking brake.
2. Lift that corner and spin the wheel by hand with the transmission in neutral. Some drag is normal; a wheel you can barely turn is not.
3. Pull the wheel and look at the pads. Compare inner and outer thickness. A big difference means the caliper is not sliding.
4. Check the slide pins. They should move in and out with hand pressure. Pins that are rusted, bent or stuck need attention.
5. Look at the piston boot and the caliper body for wetness. Any fluid means the caliper is leaking and should be replaced.
6. On the rear, remove the rotor and inspect the parking brake shoes and adjuster before blaming the caliper.

If the pins are only dry and the piston moves freely, cleaning and relubricating the pins with new boots may be enough. If the piston is rusted, the boot is torn, or there is any leak, replace the caliper.

The Fix: Which Parts to Replace Together

Replace calipers in pairs on the same axle. A new caliper on one side and a tired one on the other is a recipe for a pull. Remanufactured calipers are the usual choice for a truck this age; Ford itself lists remanufactured rear calipers for the 2005 Expedition, and Cardone's reman units come with new seals, a new bleeder and new mounting hardware. You can find replacement units in our brake calipers for trucks and SUVs.

Along with the calipers, plan on:

• Pads. A dragging caliper usually overheats or unevenly wears the pads. Fit new brake pads on the whole axle.
• Rotors. A caliper that stuck long enough to overheat the pads often leaves the rotor with heat discoloration or thickness variation, which you feel as a pedal pulsation. Our replacement brake rotors cover this.
• Hardware. Brake and Front End recommends replacing all mounting hardware when installing a replacement caliper and using proper high-temperature caliper lubricant on sleeves, bushings, pins and sliding surfaces. A brake hardware kit is inexpensive insurance.
• Brake hoses. Rubber hoses on a truck this age can crack or deteriorate internally, which can hold pressure on a caliper and cause the same drag symptom. Inspect them and replace any that are cracked or swollen with new brake hoses.
• Fluid. Opening the system means bleeding it. Use the fluid type printed on the reservoir cap or in the owner's guide, and never add DOT 5 fluid to a system that specifies DOT 3 or DOT 4, which Ford warns can damage the brake system.

If you are doing both axles at once, a complete kit is the simplest route. We carry a 2003-2006 Ford Expedition front and rear brake kit that covers the pads and rotors for this truck.

How Hard Is the Job?

For someone who has done a pad and rotor job before, a caliper swap on this Expedition is a manageable driveway job. The front caliper is held by two Torx-head bolts (a T45 on many trucks, a T40 in some model years), so have the right Torx sockets before you start. Remove the caps over the bolts, remove the bolts, spread the pads slightly, lift the caliper off, and support it so it never hangs by the brake hose.

The extra work compared with a pad job is the hydraulics: disconnect the hose at the caliper (use new sealing washers on a banjo fitting), install the new caliper, and bleed the system until the pedal is firm with no air. The rear adds the parking brake: if the rotor will not come off because the shoes are adjusted out against the hat, back off the adjuster before pulling it.

Tighten caliper and bracket bolts to the values in the factory service manual, and torque the wheel lug nuts in a star pattern. After the job, pump the pedal until it is firm before moving the truck, then bed in the new pads with a series of moderate stops.

Frequently Asked Questions

Can I replace just one caliper on my Expedition?

You can, but it is better to replace both calipers on the same axle. A new caliper paired with an old one can apply and release differently and cause a pull. At a minimum, service the pins and hardware on the other side.

Does the 2003-2006 Expedition have rear disc brakes?

Yes. It uses discs at all four wheels. The rear rotors also contain a small drum-in-hat parking brake with its own shoes and adjuster.

Why is only my inner pad worn down?

On a floating caliper, the pistons push the inner pad directly. If the slide pins are seized, the caliper cannot slide to apply the outer pad, so the inner pad does most of the work and wears out first. Service or replace the pins, and check the caliper.

Should I buy loaded or unloaded calipers?

An unloaded caliper comes without pads so you can choose your own. A loaded caliper comes with pads installed, which saves time. Either works; what matters is that the caliper matches your year and position and that you install new hardware.

Do I need to bleed the brakes after replacing a caliper?

Yes. Opening the hydraulic line lets air in. Bleed that caliper at minimum, and many techs flush the whole system at the same time if the fluid is dark or old.

Sources

1. Cardone 18-B4828 caliper - fits 2003-2006 Expedition and Navigator; two-piston floating design, cast iron, new seals and hardware
2. Cardone 18-4856 caliper - a separate two-piston caliper listed for 2003 only with a different piston size
3. Ford parts catalog, 2005 Expedition rear brakes - rear calipers, brackets, rotors, remanufactured calipers and parking brake shoe kit
4. GTSparkplugs Expedition front brake replacement - Torx T45 (T40 in some years) caliper bolts and removal steps
5. Brake and Front End tech tip - causes of slider caliper binding; replace hardware and use high-temperature lubricant
6. ADVICS slide pin troubleshooting - symptoms and causes of sticking slide pins
7. Ford brake fluid how-to - a falling fluid level means service is needed; never add DOT 5 to DOT 3 or DOT 4 systems
8. NHTSA recall data, 2004 Ford Expedition - no brake caliper recalls listed