Replace the ABS module (hydraulic control unit) on a 2021-2024 Ford F-150 with 3.5L EcoBoost engine, including brake line disconnection, module removal, installation, and complete brake system bleeding.

Warnings

Tools required

Parts

• ABS module (Hydraulic Control Unit) × 1 — Use OEM Ford part
• Brake line crush washers × 4 — Replace if equipped
• Brake fluid × 1 — Motorcraft DOT 4 LV

Fluids

• Motorcraft DOT 4 LV Brake Fluid — 1 qt

Preparation

1. Park vehicle on level surface and engage parking brake. Chock rear wheels securely.
2. Disconnect negative battery terminal and wait 2 minutes for airbag system to discharge.
3. Use fluid extractor or turkey baster to remove as much brake fluid as possible from master cylinder reservoir to minimize spillage.
4. Raise front of vehicle and support securely on jack stands rated for vehicle weight.
5. Remove both front wheels.
6. Place drain pans under ABS module location to catch brake fluid.
7. Have at least 1 quart of fresh Motorcraft DOT 4 LV brake fluid available.
8. Ensure OBD-II scan tool has Ford-specific ABS bleeding capability or dealer-level tool is available.

Procedure

1. 1

   Access ABS module
   Open hood and locate the ABS module on the driver side of the engine bay, mounted to the frame rail near the brake master cylinder. Remove any plastic covers or air intake components blocking access to the module and brake lines. On some configurations, the battery or battery tray may need repositioning for better access.
2. 2

   Disconnect electrical connector
   Locate the large electrical connector on the ABS module. Press the locking tab and carefully pull the connector straight out from the module. Do not pull on wires. Inspect connector pins for corrosion or damage. If connector is difficult to remove, check for secondary locking tabs.
   ⚠The electrical connector contains multiple pins. Forcing it can cause permanent damage requiring expensive repairs.
3. 3

   Mark and disconnect brake lines
   Identify all brake lines connected to the ABS module (typically 4 lines). Use a paint marker or tape to label each line and its corresponding port on the module for correct reinstallation. Using the appropriate size flare nut wrench (typically 10mm or 12mm), carefully loosen each brake line fitting. Position drain pans to catch fluid. Once loosened, unscrew fittings by hand and immediately plug open lines with clean rubber caps or tape to prevent contamination.
   ⚠Use only flare nut wrenches on brake line fittings. Standard wrenches will round off the soft brass fittings, requiring line replacement.
   ⚠Brake fluid will begin draining immediately. Have drain pans positioned before loosening fittings.
4. 4

   Remove ABS module mounting bolts
   Locate the mounting bolts securing the ABS module to the mounting bracket (typically 2-3 bolts). Using appropriate socket (typically 10mm or 13mm), remove all mounting bolts. Support the module while removing the last bolt as the module is heavy when filled with fluid.
   ⚠The ABS module weighs approximately 5-7 pounds and contains residual brake fluid. Support it during removal to prevent dropping.
5. 5

   Remove old ABS module
   Carefully lift the old ABS module away from the mounting bracket. Keep it upright to minimize fluid spillage. Place the old module in drain pan. Allow remaining brake fluid to drain completely. Inspect mounting bracket for corrosion or damage.
6. 6

   Prepare new ABS module
   Remove new ABS module from packaging. Verify part number matches old module and vehicle specifications. Inspect all ports for shipping plugs or caps and remove them. Check that the electrical connector on new module matches the vehicle connector. If crush washers are used on brake line fittings, install new ones now.
7. 7

   Install new ABS module
   Position the new ABS module onto the mounting bracket, aligning all mounting holes. Install mounting bolts hand-tight first to ensure proper alignment. Once all bolts are started, torque the ABS module mounting bolts to specification in a cross-pattern to ensure even clamping force.
   ⚠Do not overtighten ABS module bolts. The module housing is aluminum and threads can strip easily.
   Torque spec

   ABS Module Bolts10 Nm (7 lb-ft)
8. 8

   Reconnect brake lines
   Remove plugs from brake lines and ABS module ports. Referring to your labels from removal, thread each brake line fitting into the correct port by hand to avoid cross-threading. Once all fittings are hand-tight and properly seated, use the flare nut wrench to torque each brake line fitting to specification. Torque in multiple stages, alternating between fittings.
   ⚠Thread fittings by hand first. If a fitting does not thread easily, do not force it. Cross-threaded fittings will leak and require module replacement.
   Torque spec

   Brake Line Fittings15 Nm (11 lb-ft)
9. 9

   Reconnect electrical connector
   Align the electrical connector with the module socket, ensuring the orientation is correct. Press firmly until you hear and feel the locking tab click into place. Gently tug on the connector to verify it is fully locked.
10. 10

    Reinstall wheels and lower vehicle
    Reinstall both front wheels. Install lug nuts hand-tight first, then torque in a star pattern to specification. Lower vehicle from jack stands. With vehicle on ground, perform final torque on wheel lug nuts in star pattern.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)
11. 11

    Fill master cylinder reservoir
    Fill the brake master cylinder reservoir to the MAX line with fresh Motorcraft DOT 4 LV brake fluid from a sealed container. Do not overfill. Keep reservoir covered when not actively adding fluid to prevent contamination.
12. 12

    Perform manual brake bleeding
    Bleed all four brake calipers in this order: right rear, left rear, right front, left front. For each wheel: attach bleeder hose to bleeder screw and place other end in container with clean brake fluid. Have assistant press brake pedal slowly 3-4 times and hold. Open bleeder screw 1/2 turn, allow fluid and air to escape, then close bleeder screw before assistant releases pedal. Repeat until fluid flows with no air bubbles. Torque bleeder screws to specification. Check and refill master cylinder reservoir frequently.
    ⚠️Never allow master cylinder reservoir to run empty during bleeding. This will introduce air into the ABS module, requiring complete system re-bleeding.
    ⚠Bleeder screws are brass and fragile. Do not overtighten or they will break, requiring caliper replacement.
    Torque spec

    Bleeder Screw16 Nm (12 lb-ft)
13. 13

    Perform ABS module bleeding with scan tool
    Reconnect negative battery terminal. Connect OBD-II scan tool with ABS bleeding capability. Navigate to ABS system bleeding function. Follow scan tool prompts to activate ABS pump and cycle solenoid valves. This typically involves multiple cycles while monitoring brake pedal or performing additional manual bleeding at calipers. This step is CRITICAL and cannot be skipped. The ABS module contains internal valves that trap air and cannot be bled manually.
    ⚠️ABS module bleeding with a professional scan tool is MANDATORY. Without this step, air will remain trapped in the ABS module, causing brake failure during ABS activation.
    ⚠If you do not have access to a scan tool with Ford ABS bleeding capability, this job must be completed at a dealership or professional shop.
14. 14

    Verify brake pedal feel
    With engine off, pump brake pedal 15-20 times. Pedal should become firm and maintain height. If pedal feels spongy or sinks slowly, additional bleeding is required. Start engine and verify pedal remains firm with slight drop when engine starts (normal for power brakes). Check for any brake fluid leaks at all line connections and bleeder screws.
    ⚠️If brake pedal feels soft, spongy, or travels more than halfway to floor, DO NOT DRIVE the vehicle. Additional bleeding is required.
15. 15

    Check and clear fault codes
    Using scan tool, check for any ABS or brake system fault codes. Clear any stored codes related to the module replacement. If new codes appear or certain codes will not clear, module programming may be required. Some replacement ABS modules require dealer programming or configuration to match vehicle VIN and options.
    ⚠Some ABS modules require dealer-level programming. Verify with your parts supplier whether programming is required for your specific replacement module.

Reassembly

1. Reinstall any plastic covers, air intake components, or battery components removed for access.
2. Top off brake fluid reservoir to MAX line with fresh Motorcraft DOT 4 LV fluid.
3. Clean any brake fluid spills from painted surfaces immediately with water.
4. Dispose of old brake fluid and contaminated shop towels according to local hazardous waste regulations.

Verification

• With engine running, verify brake pedal is firm and does not sink when held under pressure for 30 seconds.
• Inspect all brake line connections and bleeder screws for any signs of fluid leaks.
• Test drive vehicle in safe area with no traffic at speeds under 15 mph. Verify normal brake operation and pedal feel.
• Perform several moderate brake applications to verify proper function.
• Accelerate to 15-20 mph and perform ABS test on safe surface (loose gravel or wet pavement) to verify ABS activates properly with pulsing pedal feedback.
• Using scan tool, verify no ABS fault codes are present and ABS warning light is off.
• After test drive, recheck all brake line connections for leaks and recheck brake fluid level.
• If everything checks out, gradually increase test speeds and brake intensity before returning to normal driving.
• Recheck brake fluid level after first 50 miles of driving.

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