Fuel Pump

Remove and replace the fuel pump module assembly by dropping the fuel tank from a 2005 Dodge Viper, requiring fuel system depressurization and tank support.

Warnings

Tools required

Parts

• Fuel pump module assembly × 1 — Use OEM specification or equivalent (Mopar 5093457AA or aftermarket)
• Fuel pump module O-ring seal × 1 — Use OEM specification
• Fuel filter (integrated in pump module) × 1 — Typically included with pump module assembly

Preparation

1. Park vehicle on level ground and engage parking brake. Ensure adequate workspace around rear of vehicle.
2. Position Class B fire extinguisher within immediate reach of work area.
3. Relieve fuel system pressure: Remove fuel pump relay (located in PDC under hood), then start engine and allow it to run until it stalls. Attempt restart to confirm no residual pressure.
4. Disconnect negative battery cable and isolate terminal away from battery post.
5. Drain fuel tank to approximately 1/4 full or less to reduce weight. Use approved fuel storage containers in well-ventilated area. Document current fuel level if unable to drain.
6. Raise rear of vehicle and support securely on jack stands rated for vehicle weight. Ensure stands are positioned on proper frame contact points.
7. Allow exhaust system to cool completely if vehicle was recently operated (minimum 1 hour cool-down time).

Procedure

1. 1

   Remove Fuel Filler Neck and Vent Line
   Working at the right rear quarter panel area, locate the fuel filler neck connection to the tank. Loosen the hose clamp securing the filler neck to the tank inlet using a flat-blade screwdriver or appropriate socket. Remove the clamp and carefully separate the filler neck from the tank. Locate and disconnect the vent line from the tank by releasing its hose clamp and removing the line. Be prepared for residual fuel spillage; have shop towels ready.
2. 2

   Disconnect Fuel Lines and Electrical Connector
   Locate the fuel supply and return lines at the front of the fuel tank. These are quick-disconnect fittings. Using the appropriate fuel line disconnect tool (typically push-to-release style), depress the release tabs and pull the lines straight off the pump module connections. Expect residual fuel to drain; catch with shop towels. Locate the fuel pump module electrical connector on top of the tank. Press the release tab and disconnect the harness. Route the harness clear of the tank.
3. 3

   Disconnect EVAP Lines
   Identify the EVAP vapor lines connected to the fuel tank (typically near the front or side of tank). These may include lines to the charcoal canister and leak detection pump. Disconnect these lines using appropriate disconnect tools or by releasing spring clamps. Label connections if needed for reassembly reference. Cap or plug open lines to prevent contamination.
4. 4

   Support Fuel Tank
   Position a fuel tank support jack or transmission jack under the center of the fuel tank. Raise the jack until it makes contact with the tank bottom, providing support but not lifting the tank. Use a wide wooden block or tank support saddle to distribute load evenly and prevent tank damage. Ensure the tank is stable on the jack before proceeding.
5. 5

   Remove Tank Support Straps
   Locate the two fuel tank support straps that loop under the tank and bolt to the chassis on each side. Remove the rear mounting bolts from both straps, then remove the front mounting bolts. Verify the number of bolts securing each strap against factory service data before removal (typically 2 bolts per strap, one per end). Support the straps as you remove the final bolts to prevent them from falling. Once all bolts are removed, pivot the straps down and away from the tank.
   Torque spec

   Tank Strap Bolts35 Nm (26 lb-ft)
6. 6

   Lower and Remove Fuel Tank
   Carefully lower the fuel tank support jack, monitoring all connections to ensure nothing is still attached. Lower the tank approximately 12 inches and verify all lines, hoses, and electrical connections are disconnected. Continue lowering the tank fully and maneuver it out from under the vehicle. Place the tank on a clean work surface. Clean the top of the tank thoroughly around the fuel pump module access area using shop towels and parts cleaner to prevent contamination.
7. 7

   Remove Fuel Pump Lock Ring
   Using the fuel pump lock ring spanner tool, engage the tool tangs into the notches on the lock ring. The lock ring turns counterclockwise to loosen (standard direction). Tap the tool handle with a plastic mallet if needed to break the ring loose. Once loose, unscrew the lock ring by hand and remove it completely. Set aside on a clean surface.
8. 8

   Remove Fuel Pump Module Assembly
   Carefully lift the fuel pump module assembly straight up and out of the fuel tank opening. Tilt the module slightly to clear the tank opening while keeping the float arm and fuel level sender intact. Be aware that the fuel pump reservoir will contain residual fuel; drain this into the tank or an approved container. Inspect the module mounting flange and tank opening for debris or damage. Remove and discard the old O-ring seal from the tank opening.
9. 9

   Install New Fuel Pump Module
   Install the new O-ring seal onto the fuel tank opening, ensuring it seats properly in the groove. Verify the O-ring is not twisted or damaged. Carefully lower the new fuel pump module assembly into the tank opening, aligning the module orientation to match the fuel line port positions. The float arm must be oriented toward the rear of the tank and the module should sit flush against the tank opening with the O-ring compressed evenly.
10. 10

    Install and Torque Lock Ring
    Place the lock ring over the fuel pump module and thread it clockwise by hand until it is finger-tight against the module flange. Using the fuel pump lock ring spanner tool and torque wrench, tighten the lock ring to the manufacturer-specified torque (verify factory spec; typical lock ring values are much lower than 80 Nm). Ensure even compression of the O-ring by checking that the lock ring sits flat against the tank surface around the entire circumference.
    Torque spec

    Fuel Pump Module Lock Ring80 Nm (59 lb-ft)
11. 11

    Reinstall Fuel Tank
    Clean the tank mounting surfaces and strap contact areas. Position the fuel tank on the support jack and carefully raise it into position under the vehicle. Align the tank with the mounting strap locations and ensure all hose/line routing paths are clear. Raise the tank until it contacts the chassis mounting points.
12. 12

    Install Tank Support Straps
    Position the tank support straps over the tank and align the strap ends with the chassis mounting holes. Install all strap mounting bolts hand-tight first to ensure proper alignment. Once all bolts are started, torque each bolt to the manufacturer-specified value alternately/evenly to ensure even loading (verify strap bolt torque against factory service data).
    Torque spec

    Tank Strap Bolts35 Nm (26 lb-ft)
13. 13

    Reconnect All Lines and Electrical
    Reconnect the fuel supply and return lines to the pump module by pushing them onto the fittings until they click into place. Tug each line to verify secure connection. Reconnect the EVAP vapor lines to their respective ports, ensuring all clips or clamps are fully engaged. Connect the fuel pump module electrical connector until it clicks, verifying the lock tab engages. Reconnect the fuel filler neck to the tank inlet and secure with the hose clamp tightened firmly. Reconnect the vent line and secure its clamp.
14. 14

    Final Checks and Battery Reconnection
    Remove the fuel tank support jack. Perform a final visual inspection under the vehicle to verify all connections are secure, no tools or parts are left behind, and all fasteners are installed. Lower the vehicle from jack stands. Reconnect the negative battery cable. Reinstall the fuel pump relay in the PDC.

Reassembly

1. Installation follows removal in reverse order with the following critical points:
2. Always use a NEW fuel pump module O-ring seal. Do not reuse the old seal.
3. Verify correct fuel pump module orientation before tightening lock ring—the float arm must face toward the rear of the tank.
4. Torque all fasteners to specification. Do not overtighten tank strap bolts as this can deform the tank.
5. Ensure all fuel line quick-connect fittings click fully into place and are pull-tested for security.

Verification

• Turn ignition key to RUN position (do not start) for 2 seconds, then OFF. Repeat this cycle 3-4 times to allow fuel pump to prime the system and build pressure.
• Inspect all fuel line connections, tank seams, and pump module area for fuel leaks. Use a flashlight and check carefully—fuel leaks may be small initially.
• Start the engine and allow it to idle. Monitor for smooth operation and any fuel odor or visible leaks under the vehicle.
• Check fuel gauge operation to verify the fuel level sender is functioning correctly.
• Perform a test drive and monitor for proper fuel delivery, no hesitation, and no fuel odor in cabin or from tank area.
• After test drive, perform final leak inspection with vehicle on level ground and engine at operating temperature.

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