🔧 Fuel Pump Module - Replacement

The fuel pump on your Sierra sits inside the fuel tank, so the tank has to be lowered to replace the pump module. This is a labor-heavy repair, but it is very doable with basic hand tools, a safe lifting setup, and care around fuel vapors.

Difficulty Level: Advanced | Estimated Time: 4-6 hours

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⚠️ Safety & Precautions

• Work only outdoors or in a very well-ventilated area. Fuel vapors are flammable.
• Do not smoke, weld, grind, or use heat near the vehicle.
• Disconnect the negative battery cable before starting.
• Relieve fuel pressure before opening any fuel lines.
• Support the fuel tank securely with a transmission jack or a wide floor jack.
• Keep a fire extinguisher nearby.
• Wear safety glasses and fuel-resistant gloves.

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🔧 Required Tools

You'll need the following tools for this repair:

• 3/8-inch drive ratchet
• 8mm socket
• 10mm socket
• 13mm socket
• 15mm socket
• 18mm socket
• Extensions
• Fuel line disconnect tool set (specialty)
• Flat-blade screwdriver
• Torque wrench
• Floor jack rated 3-ton minimum
• Jack stands rated for truck weight
• Transmission jack or wide support jack
• Fuel-safe drain pan
• Shop towels
• Safety glasses
• Nitrile gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Fuel pump module - Qty: 1
• Fuel tank seal / O-ring - Qty: 1
• Fuel filter - Qty: 1
• Fuel tank strap bolts - Qty: 2
• Fuel line seal kit - Qty: 1
• Fuel pump relay - Qty: 1

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Run the fuel level down as low as possible before starting. A near-empty tank is much easier and safer to lower.
• Disconnect the negative battery cable before touching the fuel system.
• Use a scan tool or cycle the ignition off if the truck has been running recently, then wait a few minutes to reduce fuel pressure.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Relieve fuel system pressure

• Disconnect the negative battery cable using a 10mm socket.
• Remove the fuel pump relay from the underhood fuse block with your fingers or a small trim tool.
• Start the engine and let it run until it stalls. Crank for a few more seconds, then turn the key off.
• Cranking after stall bleeds off leftover pressure.

Step 2: Raise and support the truck

• Lift the rear of the truck with a floor jack rated 3-ton minimum.
• Support the frame securely with jack stands rated for truck weight.
• Make sure the truck is stable before working underneath it.

Step 3: Remove fuel tank shields and filler connections

• Use an 8mm socket and 10mm socket to remove any tank shield fasteners or skid plate bolts.
• Loosen the fuel filler neck and vent hose connections as equipped.
• Use a flat-blade screwdriver to release hose clamps where applicable.

Step 4: Disconnect fuel and electrical connections

• Use the fuel line disconnect tool set (specialty) to separate the fuel supply line at the tank.
• Unplug the electrical connector at the fuel pump module.
• Disconnect any EVAP or vent hoses attached to the tank.
• Label hoses if needed so they go back in the correct place.

Step 5: Support and lower the fuel tank

• Place a transmission jack or wide support jack under the tank.
• Use a 15mm socket or 18mm socket to remove the fuel tank strap bolts.
• Lower the tank slowly and check for any hoses or wires still attached.
• Remove the tank from under the truck once it is free.

Step 6: Remove the old fuel pump module

• Clean the top of the tank with shop towels before opening it.
• Use a flat-blade screwdriver or lock ring tool if equipped to remove the pump lock ring.
• Lift the fuel pump module straight out of the tank.
• Remove the old seal and inspect the tank opening for dirt or damage.

Step 7: Install the new fuel pump module

• Install the new fuel tank seal / O-ring in the tank opening.
• Lower the new fuel pump module into the tank carefully so the float arm is not bent.
• Install the lock ring and tighten it fully by hand, then seat it securely with the proper tool if needed.
• Keep dirt out of the tank.

Step 8: Reinstall the fuel tank

• Raise the tank back into position with the transmission jack or wide support jack.
• Reconnect the EVAP hoses, filler neck, and electrical connector.
• Reconnect the fuel line using the fuel line disconnect tool set (specialty) if needed to lock it fully.
• Install the tank straps and tighten the bolts to Torque to 35 Nm (26 ft-lbs).
• Reinstall any tank shields and tighten fasteners to Torque to 10 Nm (89 in-lbs).

Step 9: Restore power and prime the system

• Reconnect the negative battery cable with a 10mm socket.
• Reinstall the fuel pump relay.
• Turn the ignition key to ON for 5 seconds, then OFF. Repeat this 3 times to prime the system.
• Start the engine and let it idle.

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✅ After Repair

• Inspect the tank, fuel line connections, and filler neck for leaks with the engine running.
• Check for fuel smell around the truck and under the tank area.
• Clear any stored fuel system codes with a scan tool if needed.
• Test drive the truck and confirm normal starting, idle, and acceleration.

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💰 DIY vs Shop Cost

Shop Cost: $900-$1,600 (parts + labor)

DIY Cost: $250-$650 (parts only)

You Save: $650-$950 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 4-6 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.