This procedure replaces the fuel pump module assembly in the fuel tank of a 2015-2020 Ford F-150 with the 3.5L EcoBoost V6 engine, requiring tank access and fuel system depressurization.

Warnings

Tools required

Parts

• Fuel pump module assembly × 1 — Motorcraft PFS-540 or equivalent
• Fuel pump lock ring seal (O-ring) × 1 — Use OEM specification
• Fuel line O-rings × 2 — Use OEM specification

Preparation

1. Verify fuel tank is no more than 1/4 full. If more than 1/4 full, drain fuel using approved fuel transfer equipment into approved containers
2. Park vehicle on level ground in a well-ventilated area away from ignition sources, pilot lights, and sparks
3. Place fire extinguisher within easy reach
4. Disconnect negative battery terminal and wait at least 2 minutes for fuel pump to stop and pressure to drop
5. Relieve any remaining fuel system pressure by removing the fuel pump relay (location: power distribution box under hood, relay R5) and attempting to start the engine until it will not run
6. Reinstall fuel pump relay after engine stops running
7. Gather all tools and new parts including fuel pump module, lock ring seal, and fuel line O-rings
8. Remove rear seat cushion by pulling up firmly on front edge to release clips (provides access to fuel pump access cover)

Procedure

1. 1

   Access fuel pump module
   Locate the fuel pump access cover in the floor under the rear seat. The cover is a plastic or metal panel with multiple screws. Use a flat blade screwdriver or appropriate socket to remove all access cover screws. Carefully lift the cover away, exposing the fuel pump module top and electrical connector. Clean the area thoroughly with a rag to prevent debris from entering the tank.
2. 2

   Disconnect electrical connector
   Press down on the gray locking tab of the fuel pump module electrical connector and pull the connector straight up to disconnect. The connector is a large multi-pin connector on top of the module. Ensure it is fully disconnected and position it away from the work area.
3. 3

   Disconnect fuel supply line
   Locate the fuel supply line connected to the top of the fuel pump module. This is a spring-lock coupling. Use the appropriate fuel line disconnect tool (typically 3/8") by inserting it into the coupling and pushing toward the module while pulling the line away. Have shop towels ready as residual fuel will drain. Place towels or a catch pan under the connection. Inspect the O-ring on the fuel line and replace if damaged.
   ⚠Residual fuel under pressure may spray when disconnecting. Keep face and ignition sources away from connection point.
4. 4

   Disconnect vapor line (if equipped)
   If present, disconnect the fuel vapor return line using the smaller fuel line disconnect tool (typically 5/16"). Follow the same procedure as the supply line. Not all configurations have an external vapor line connection at the pump module.
5. 5

   Remove fuel pump lock ring
   Using the fuel pump lock ring tool (Ford Tool 310-123 or equivalent), position the tool tangs into the lock ring slots. The lock ring rotates counterclockwise to loosen. Apply steady counterclockwise force to break the lock ring free. Once loose, unthread the lock ring completely by hand or with the tool and remove it. Place it aside with the old seal still attached for reference.
   ⚠Do not strike or use excessive force on the lock ring as this can damage the tank or create sparks.
6. 6

   Remove fuel pump module assembly
   Carefully lift the fuel pump module straight up out of the fuel tank opening. The module includes a float arm and fuel level sender that must clear the opening. Tilt the module slightly if needed to maneuver the float arm out. Be prepared for fuel to drain from the module—have a catch pan ready. Once removed, drain remaining fuel from the module into an approved container. Inspect the module opening in the tank for debris.
   ⚠Fuel will drain from the module as it is removed. Use catch pan and have towels ready.
7. 7

   Remove and inspect old lock ring seal
   Remove the old rubber seal (O-ring) from the lock ring or tank opening. Inspect the sealing surface on the fuel tank for damage, corrosion, or debris. Clean the sealing surface thoroughly with a lint-free cloth. Any debris left on this surface will cause a fuel leak.
8. 8

   Prepare new fuel pump module
   Remove the new fuel pump module from its packaging. If the new module does not include a float arm or fuel level sender, carefully transfer these components from the old module to the new one according to the manufacturer's instructions. Install the new lock ring seal (O-ring) onto the new fuel pump module flange, ensuring it seats properly in the groove. Lightly lubricate the seal with clean gasoline to aid installation.
9. 9

   Install new fuel pump module
   Carefully lower the new fuel pump module into the fuel tank opening, maneuvering the float arm and sender through the opening. Ensure the module is oriented correctly—there is typically an alignment arrow or mark on the module flange that must align with a mark on the tank. Press the module down firmly to compress the seal against the tank opening. Ensure the seal is not pinched or twisted.
10. 10

    Install and torque lock ring
    Thread the lock ring onto the fuel tank opening by hand in a clockwise direction until it contacts the module flange. Using the fuel pump lock ring tool, torque the lock ring to specification. Apply steady clockwise rotation with the tool while monitoring torque. The lock ring compresses the seal to create a fuel-tight connection. Verify the module does not rotate with the lock ring.
    ℹ️Proper lock ring torque is critical to prevent fuel leaks. Use a torque wrench or calibrated lock ring tool.
    Torque spec

    Fuel Pump Lock Ring78 Nm (58 lb-ft)
11. 11

    Connect fuel supply line
    Install new O-rings on the fuel supply line if not already installed. Push the fuel supply line straight onto the fuel pump module fitting until it clicks into place. Pull back on the line to verify it is locked. The spring-lock coupling should be fully engaged and secure. If the line fitting requires torquing (some models have threaded fittings), torque to specification.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
12. 12

    Connect vapor line and electrical connector
    If equipped, connect the fuel vapor line using the same procedure as the supply line. Connect the electrical connector to the fuel pump module by pressing it straight down onto the module terminal until the locking tab clicks into place. Verify the connector is fully seated and locked.
13. 13

    Reinstall access cover and rear seat
    Position the fuel pump access cover over the opening, ensuring any alignment features are correct. Install all access cover screws and torque to specification using a torque wrench or screwdriver with appropriate feel to avoid overtightening the plastic panel. Reinstall the rear seat cushion by positioning the rear hooks into the slots and pressing down firmly on the front edge until the clips engage.
    Torque spec

    Access Cover Screws5 Nm (3 lb-ft)
14. 14

    Reconnect battery and prime fuel system
    Reconnect the negative battery terminal. Turn the ignition key to the ON position (do not start engine) for 5 seconds, then OFF for 5 seconds. Repeat this cycle 4-5 times to allow the fuel pump to prime the system and build pressure. Listen for the fuel pump running during each ON cycle. Check all connections at the fuel pump module for leaks during and after priming.
    ⚠️Inspect for fuel leaks immediately during priming. Any leak must be corrected before starting the engine.

Reassembly

1. Ensure all fuel line connections are secure and properly locked
2. Verify electrical connector is fully seated with locking tab engaged
3. Confirm access cover is securely fastened with all screws torqued properly
4. Verify rear seat cushion is fully latched in place

Verification

• With ignition ON (engine not running), listen for fuel pump operation for approximately 2 seconds—this confirms electrical operation
• Inspect the fuel pump access cover area and all visible connections for fuel leaks or fuel odor
• Start the engine and allow it to idle for 2-3 minutes while monitoring for leaks, rough running, or warning lights
• Check for diagnostic trouble codes (DTCs) using a scan tool—no fuel system codes should be present
• Rev engine to 2500 RPM and verify smooth operation without hesitation or fuel pressure issues
• Perform a test drive and verify normal acceleration, no surging, and no fuel odor in or around the vehicle
• After test drive, re-inspect all connections at the fuel pump module for leaks with the access cover removed
• Verify fuel gauge reads correctly and matches actual fuel level in tank

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