This procedure covers removal and replacement of the ABS hydraulic control unit (HCU/pump) on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine, including brake line disconnection, module removal, and system bleeding.

Warnings

Tools required

Parts

• ABS hydraulic control unit (pump assembly) × 1 — Use OEM specification
• Brake fluid reservoir cap seal (if damaged) × 1 — Use OEM specification

Fluids

• Motorcraft DOT 4 LV Brake Fluid — 1.5 qt

Preparation

1. Park vehicle on level ground and set parking brake
2. Disconnect negative battery cable and wait 2 minutes for airbag system to discharge
3. Remove as much brake fluid as possible from reservoir using turkey baster or fluid extractor
4. Raise and support vehicle on jack stands at all four corners
5. Remove all four wheels to access brake bleeders later
6. Have clean shop towels and drain pan ready to catch brake fluid spills

Procedure

1. 1

   Depressurize ABS system
   With ignition off and battery disconnected, press and release brake pedal firmly 25-30 times to depressurize the hydraulic accumulator in the ABS module. This prevents sudden fluid discharge when lines are disconnected.
2. 2

   Locate and access ABS module
   The ABS hydraulic control unit is mounted on the driver side frame rail near the master cylinder. From under the vehicle, identify the module with six brake lines connected. Remove any plastic shields or covers blocking access to the module mounting area.
3. 3

   Disconnect electrical connector
   Locate the main electrical connector on the ABS module. Press the locking tab and carefully disconnect the harness connector. Move the wiring harness aside to prevent damage during removal.
4. 4

   Label and disconnect brake lines
   Using masking tape or marker, label all six brake lines at the ABS module (left front, right front, left rear, right rear, and two master cylinder lines) for correct reinstallation. Using flare nut wrenches to prevent rounding, carefully loosen and disconnect each brake line. Immediately cap or plug each line and port to prevent fluid loss and contamination. Have drain pan positioned to catch fluid.
   ⚠Use flare nut wrenches only. Standard wrenches will round off the soft brass fittings.
5. 5

   Remove ABS module mounting bolts
   Locate the mounting bolts securing the ABS module to the bracket (typically 2-3 bolts). Remove these bolts using appropriate socket. Support the module weight as you remove the final bolt, as the unit is heavy and contains residual brake fluid.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
6. 6

   Remove ABS module
   Carefully lower the ABS module assembly from its mounting position. Tilt it appropriately to minimize fluid spillage from the internal passages. Place the old module in drain pan. Inspect the mounting bracket for damage or corrosion and clean if necessary.
7. 7

   Prepare new ABS module
   Unpack new ABS module and verify it matches the old unit exactly. Remove all shipping caps from brake line ports on the new module just before installation. Inspect all ports for cleanliness and ensure no contamination enters the system.
8. 8

   Install new ABS module
   Position the new ABS module onto the mounting bracket, aligning it with the bolt holes. Hand-thread all mounting bolts first to ensure proper alignment, then torque mounting bolts to specification in a cross pattern.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
9. 9

   Reconnect brake lines
   Remove caps/plugs from brake lines and new module ports. Using your labels as reference, thread each brake line into the correct port on the ABS module by hand first to prevent cross-threading. Tighten each fitting with flare nut wrench until snug, ensuring fittings seat properly. Do not overtighten as brass fittings can strip easily.
   ⚠Start each fitting by hand and ensure threads engage smoothly before using wrench. Cross-threaded fittings will leak and require line replacement.
10. 10

    Reconnect electrical connector
    Reconnect the main electrical harness connector to the ABS module, ensuring it clicks fully into place. Verify the locking tab is engaged.
11. 11

    Fill brake fluid reservoir
    Fill the master cylinder reservoir to the MAX line with fresh Motorcraft DOT 4 LV brake fluid from a sealed container. Keep reservoir full throughout the bleeding process.
12. 12

    Manual brake bleeding - initial
    Starting with the wheel furthest from the master cylinder (right rear), attach bleeder hose to bleeder screw and submerge other end in container with clean brake fluid. Have assistant pump brake pedal 3-4 times and hold pressure. Open bleeder screw, allow fluid and air to discharge, then close bleeder screw before pedal reaches floor. Repeat until fluid flows clear with no air bubbles. Repeat process for left rear, right front, then left front. Check and refill reservoir frequently to prevent air entry.
    ⚠️Never allow reservoir to run empty during bleeding or air will enter the ABS module requiring the entire process to restart.
    Torque spec

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

    Scan tool ABS module bleeding
    Reconnect battery. Using a professional scan tool with ABS bleeding capability, connect to the OBD-II port. Navigate to ABS system and initiate the automated bleeding procedure. This will cycle the ABS solenoids and pump to purge air from internal passages. Follow scan tool prompts, which typically involve running the automated cycle while monitoring brake fluid level. The scan tool will cycle each ABS valve multiple times. This step is critical and cannot be skipped.
    ℹ️Generic code readers cannot perform this function. A professional scan tool with Ford ABS bleeding capability is required.
14. 14

    Final manual bleeding
    After ABS module cycling is complete, repeat the manual bleeding process at all four wheels in the same sequence (RR, LR, RF, LF) to remove any air introduced during the automated cycle. Verify firm brake pedal feel and no air bubbles in discharged fluid.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
15. 15

    Reinstall wheels and test
    Reinstall all four wheels and torque lug nuts to specification in a star pattern. Lower vehicle to ground. Top off brake fluid reservoir to MAX line. Start engine and verify ABS warning light extinguishes after initial bulb check. Pump brake pedal multiple times and verify firm, consistent pedal feel with no sponginess.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all brake line connections are tight and show no signs of leakage
2. Verify brake fluid reservoir is filled to MAX line with DOT 4 LV fluid
3. Confirm ABS module electrical connector is fully seated and locked
4. Double-check all wheel lug nuts are torqued to specification in star pattern

Verification

• Start engine and verify ABS warning light turns off after 3-5 seconds
• Press brake pedal firmly - it should feel solid with no excessive travel or sponginess
• Perform a low-speed test drive (5-10 mph) in a safe area and verify normal brake operation
• Perform a controlled ABS activation test on dry pavement at 15-20 mph - verify ABS pulses normally without warning lights
• Inspect all brake line connections at ABS module for fluid leaks after test drive
• Use scan tool to verify no ABS fault codes are stored
• Check brake fluid level again and top off if needed - level should not have dropped significantly if system is properly bled

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