This procedure covers the replacement of the rear wheel cylinder on a 2015-2020 Ford F-150 RWD with 3.5L EcoBoost engine, including drum removal, brake component disassembly, and brake system bleeding.

Warnings

Tools required

Parts

• Rear wheel cylinder × 1 — Use OEM specification
• Brake shoe hardware kit (if worn) × 1 — Use OEM specification
• Brake drum (if damaged or worn beyond limit) × 1 — Use OEM specification

Fluids

• Motorcraft DOT 4 LV Brake Fluid — 1 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock the front wheels securely
3. Loosen rear wheel lug nuts while vehicle is on ground
4. Raise rear of vehicle and support securely on jack stands rated for vehicle weight
5. Remove rear wheel completely
6. Place drain pan under work area to catch brake fluid
7. Have adequate brake fluid on hand before starting work

Procedure

1. 1

   Remove brake drum
   Remove the brake drum by pulling it straight off the hub. If drum is stuck due to rust or shoe wear, use a rubber mallet to tap around the outer edge. If still stuck, thread two 8mm bolts into the threaded holes on the drum face and tighten evenly to push drum off hub. If shoes are holding drum, access the adjustment slot on the backing plate and rotate the adjuster star wheel to retract the shoes.
2. 2

   Inspect and photograph brake assembly
   Before disassembly, take a photo of the brake shoe and spring arrangement for reference during reassembly. Inspect the drum for scoring, heat damage, or excessive wear. Measure drum diameter and compare to service limit specification. Clean the assembly with brake cleaner and allow to dry.
3. 3

   Remove brake shoe hold-down springs
   Using brake spring pliers, remove the hold-down springs from both brake shoes. Press down on the spring retainer cup while rotating 90 degrees to disengage from the hold-down pin. Remove both springs, retainers, and pins from the leading and trailing shoes.
4. 4

   Disconnect return springs and remove shoes
   Use the brake spring tool to remove the upper and lower return springs connecting the brake shoes. Disconnect the parking brake cable from the parking brake lever on the trailing shoe. Carefully remove both brake shoes as an assembly, noting the position of the adjuster mechanism and parking brake strut.
5. 5

   Disconnect brake line from wheel cylinder
   Using a 10mm flare nut wrench, carefully loosen and disconnect the brake line fitting from the rear of the wheel cylinder. Be prepared for brake fluid to drain. Cap or plug the brake line immediately to prevent fluid loss and contamination. Do not allow brake fluid to contact the backing plate or other components.
6. 6

   Remove wheel cylinder mounting bolts
   Remove the two wheel cylinder mounting bolts from the backing plate using the appropriate socket or wrench. The wheel cylinder is typically secured with two bolts accessible from the rear of the backing plate. Remove the old wheel cylinder from the backing plate.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
7. 7

   Install new wheel cylinder
   Position the new wheel cylinder onto the backing plate, ensuring proper alignment with the brake line port. Install the two mounting bolts and torque to specification. Verify the wheel cylinder pistons move freely and dust boots are properly seated.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
8. 8

   Connect brake line to wheel cylinder
   Thread the brake line fitting into the new wheel cylinder by hand to ensure proper thread engagement. Using the 10mm flare nut wrench, tighten the fitting snugly but do not overtighten. Torque to approximately 15-18 Nm (11-13 lb-ft) to avoid damaging the fitting.
9. 9

   Reinstall brake shoes and hardware
   Lubricate the shoe contact points on the backing plate with high-temperature brake grease. Reinstall the brake shoe assembly with all springs, adjusters, and parking brake components in their original positions using your reference photo. Connect the parking brake cable to the lever. Install the hold-down springs, pins, and retainers for both shoes. Verify all springs are properly seated and shoes move freely.
10. 10

    Adjust brake shoes
    Adjust the brake shoe adjuster star wheel until the drum slides over the shoes with slight drag. Back off the adjuster 8-10 clicks until the drum rotates freely with minimal drag. This provides proper clearance while ensuring adequate braking when applied.
11. 11

    Reinstall brake drum and wheel
    Clean the hub surface and inside of the brake drum. Install the brake drum onto the hub, ensuring it seats fully. Install the wheel and thread lug nuts by hand. Torque lug nuts to specification in a star pattern.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)
12. 12

    Bleed rear brake system
    Locate the bleeder screw on the wheel cylinder. Attach a clear hose to the bleeder screw and submerge the other end in a container of clean brake fluid. Have an assistant slowly pump the brake pedal 3-4 times and hold pressure. Open the bleeder screw to release fluid and air, then close before pedal reaches the floor. Repeat until no air bubbles appear in the discharged fluid. Do not allow the master cylinder reservoir to run dry during bleeding. Torque bleeder screw to specification.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
13. 13

    Lower vehicle and perform final checks
    Remove jack stands and carefully lower the vehicle to the ground. Perform a final torque check on wheel lug nuts in a star pattern. Check brake fluid level in master cylinder reservoir and top off with Motorcraft DOT 4 LV brake fluid to the MAX line. Pump brake pedal multiple times to ensure firm pedal feel before moving vehicle.

Reassembly

1. Ensure all brake springs and hardware are properly installed and seated
2. Verify brake shoes are properly adjusted with minimal drum drag when rotated by hand
3. Confirm parking brake cable is properly connected and functions correctly
4. Double-check all brake line connections for tightness and potential leaks
5. Verify master cylinder reservoir is filled to proper level with DOT 4 LV brake fluid

Verification

• Start engine and pump brake pedal to verify firm, high pedal feel with no sponginess
• Check for brake fluid leaks at wheel cylinder and brake line connection
• Test parking brake engagement and verify it holds the vehicle on an incline
• Perform a low-speed brake test in a safe area to verify proper brake function
• Re-check brake fluid level after test drive and top off if necessary
• Verify no unusual noises, vibrations, or pulling during braking
• If this was only one wheel cylinder, schedule replacement of the opposite side wheel cylinder for balanced braking performance

More procedures for this vehicle