Fuel Pump

This procedure removes and replaces the fuel pump module in the 2007 Ram 3500 with 5.9L Cummins diesel engine by dropping the fuel tank from the vehicle.

Warnings

Tools required

Parts

• Fuel pump module assembly × 1 — Use OEM specification for 5.9L Cummins diesel
• Fuel pump module O-ring seal × 1 — Included with OEM pump or purchase separately
• Tank strap cushion pads (if deteriorated) × 2 — Use OEM specification

Preparation

1. Park vehicle on level, solid ground with adequate clearance for tank removal
2. Ensure adequate ventilation in work area and eliminate all ignition sources within 50 feet
3. Disconnect negative battery cable and isolate from battery post
4. Remove fuel filler cap to relieve any tank pressure
5. Determine fuel level - if more than 1/4 tank, drain fuel using approved transfer pump through filler neck or via tank drain plug if equipped
6. Transfer fuel to approved containers and store away from work area
7. Raise vehicle on lift or use floor jack to raise and support securely on jack stands at frame rails
8. Allow exhaust system to cool completely if vehicle was recently driven

Procedure

1. 1

   Access fuel tank area
   Position yourself under the vehicle at the fuel tank location (mounted forward of the rear axle, ahead of the axle centerline). Verify tank position for your specific cab and bed configuration. Verify tank is cool to touch. Identify the fuel pump module electrical connector on top of the tank, fuel supply and return lines, filler neck hose, vent lines, and two tank support straps.
2. 2

   Disconnect electrical connector
   Locate the fuel pump module electrical connector on top of the fuel tank. Release the connector safety lock tab and disconnect the electrical connector. Secure connector away from tank to prevent damage during removal.
3. 3

   Disconnect fuel lines
   Identify the fuel supply and return lines at the fuel pump module. Mark or label each line before disconnecting so they can be reconnected to the correct fitting. Place shop towels around connections to catch residual fuel. Press the quick-connect release tabs on each line and pull firmly to disconnect. If lines are stubborn, use a fuel line disconnect tool. Cap or plug open lines to prevent contamination.
   ⚠Expect residual diesel fuel to drain from lines. Have drip pan and towels ready.
4. 4

   Disconnect filler neck and vent lines
   At the front of the tank, locate the rubber filler neck hose secured with a hose clamp. Loosen the clamp with a flathead screwdriver or nut driver and slide it away from the tank. Twist and pull the filler neck hose off the tank inlet pipe. Disconnect the vapor vent line from the tank by pressing the quick-connect release or loosening the clamp depending on connection type.
5. 5

   Support fuel tank
   Position a transmission jack or floor jack with a block of wood centered under the fuel tank. Raise jack until it just contacts the tank and takes slight upward pressure - do NOT lift the tank yet. Ensure the tank is stable and balanced on the jack.
   ⚠️The tank with remaining fuel can weigh 80-120 pounds. Ensure jack is stable and rated for this weight. Never position yourself directly under the tank.
6. 6

   Remove tank strap bolts
   Locate the two tank support straps that loop under the tank and bolt to the frame rails. Using the correct socket size, remove the tank strap fasteners at the frame. Note the strap attachment method (bolted both ends vs. hinged/hooked one end) and count fasteners for your configuration. Apply penetrating oil if bolts are corroded. Once all bolts are removed, carefully lower and remove the straps.
   ⚠Support straps may fall once bolts are removed. Control their removal to prevent injury.
   Torque spec

   Tank Strap Bolts35 Nm (26 lb-ft)
7. 7

   Lower fuel tank
   Slowly lower the jack while guiding the tank down. Check that all lines, hoses, and electrical connections are clear. Lower tank approximately 12 inches or until you can access the top of the fuel pump module. If needed to fully remove tank, continue lowering until tank is free from vehicle. Place on stable surface if removing completely.
8. 8

   Clean pump module area
   Use shop towels to clean dirt and debris from the top of the tank around the fuel pump module lock ring. This prevents contamination from entering the tank during pump removal. Use compressed air if available to blow away loose debris.
   ⚠Any dirt entering the fuel tank can damage the new pump or contaminate the fuel system.
9. 9

   Remove fuel pump lock ring
   Using the proper fuel pump module lock ring spanner tool, engage the tool into the lock ring tabs. Rotate the lock ring counterclockwise to loosen. If tool is not available, carefully use a brass drift punch and hammer to tap the lock ring tabs counterclockwise - NEVER use steel tools that could create sparks. Remove the lock ring completely once loosened.
   ⚠️NEVER strike steel tools against the lock ring near fuel vapors. Use only brass tools or the proper locking ring tool.
   Torque spec

   Fuel Pump Module Lock Ring80 Nm (59 lb-ft)
10. 10

    Remove fuel pump module
    Carefully lift the fuel pump module straight up and out of the tank opening. Tilt the module slightly to maneuver the fuel level float arm and pickup screen through the opening. Expect residual fuel to drain from the module - have shop towels ready. Once clear of tank, place old module in a drip pan.
11. 11

    Remove and inspect O-ring seal
    Remove the large rubber O-ring seal from the groove in the tank opening. Inspect the sealing surface on the tank for damage, corrosion, or debris. Clean the sealing surface thoroughly with a lint-free cloth. Do not reuse the old O-ring.
12. 12

    Install new fuel pump module
    Install the new O-ring seal into the groove in the tank opening. Ensure it is seated properly around the entire circumference. Carefully lower the new fuel pump module into the tank opening, guiding the float arm and pickup screen. Align the module so the orientation marks match and press down until the module seats against the O-ring. Ensure the module is fully seated before proceeding.
13. 13

    Install and torque lock ring
    Place the lock ring over the fuel pump module and align the tabs. Using the lock ring tool, rotate clockwise to tighten the lock ring. Rotate the lock ring clockwise with the spanner tool until it seats fully against the stop and the alignment marks index correctly. Verify the factory torque specification for your specific module before final tightening. If using a brass punch method (not recommended), tighten firmly and evenly around the ring until fully seated - this method does not allow accurate torque verification.
    ⚠Proper lock ring torque is critical for fuel system sealing. Verify tight installation before raising tank.
    Torque spec

    Fuel Pump Module Lock Ring80 Nm (59 lb-ft)
14. 14

    Raise and position fuel tank
    Raise the tank back into position using the jack. Align the tank with the frame mounting points. Guide any lines or connectors to ensure nothing is pinched. Continue raising until tank mounting holes align with frame strap bolt holes.
15. 15

    Install tank straps and torque bolts
    Position the tank support straps over the tank and align with frame mounting holes. Install all four strap bolts finger-tight first, ensuring straps are positioned correctly. Using a torque wrench and the correct socket, torque the tank strap fasteners to the factory specification, tightening each strap evenly. Confirm fastener count and torque spec for your configuration. Remove the support jack once straps are secure.
    Torque spec

    Tank Strap Bolts35 Nm (26 lb-ft)
16. 16

    Reconnect filler neck and vent lines
    Slide the rubber filler neck hose onto the tank inlet pipe and position the hose clamp over the connection. Tighten the clamp securely. Reconnect the vapor vent line to the tank fitting until it clicks or tighten clamp as applicable.
17. 17

    Reconnect fuel lines
    Remove any caps or plugs from fuel lines. Reconnect the fuel supply line and return line to the fuel pump module fittings. Push each line firmly until you hear and feel a click indicating proper connection. Gently tug on each line to verify secure connection.
18. 18

    Reconnect electrical connector
    Reconnect the fuel pump module electrical connector. Push firmly until connector locks and red safety tab clicks into place. Verify secure connection by gently pulling on connector.

Reassembly

1. Verify all fuel lines, vent lines, and electrical connections are properly secured
2. Confirm tank straps are torqued to specification and tank is stable
3. Lower vehicle to ground
4. Reconnect negative battery cable to battery
5. If fuel was drained, refill tank with clean diesel fuel - minimum 5 gallons to submerge pump

Verification

• Turn ignition key to ON position (do not start) and listen for fuel pump to prime for 3-5 seconds. Repeat this cycle 3-4 times to prime the fuel system
• Inspect under vehicle for any fuel leaks at tank connections, pump module seal, and fuel lines
• Start engine and allow to idle. Monitor for proper operation and no warning lights
• Check under vehicle again after engine runs for 2-3 minutes to verify no leaks develop
• Test drive vehicle to confirm proper fuel delivery under load conditions
• Recheck all connections under vehicle after test drive for any signs of leakage
• If any leaks are detected, immediately shut off engine and repair before operating vehicle

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