How to Replace the Fuel Pump on a 2012 GMC Sierra 1500
Step-by-step in-tank fuel pump module replacement with tools, parts, safety tips, and torque specs for 2010, 2011, 2012, 2013
How to Replace the Fuel Pump on a 2012 GMC Sierra 1500
Step-by-step in-tank fuel pump module replacement with tools, parts, safety tips, and torque specs for 2010, 2011, 2012, 2013
🔧 Fuel Pump - Replacement
Your Sierra uses an in-tank fuel pump module, so the fuel tank must be lowered to replace it. This is a bigger job, but it is very doable at home with safe lifting support and the right tools.
Difficulty Level: Intermediate | Estimated Time: 3-5 hours
⚠️ Safety & Precautions
- Work outside or in a very well-ventilated area. Fuel vapors are flammable.
- No smoking, sparks, hot lights, or open flames near the truck.
- Relieve fuel pressure before opening any fuel lines.
- Disconnect the negative battery cable before starting.
- Use a transmission jack or floor jack with a wide support pad to lower the fuel tank safely.
- Do not let the tank hang by the filler neck or wiring.
- If your truck has a lot of fuel, drain or run it low first. A full tank is heavy and unsafe to lower.
🔧 Required Tools
You'll need the following tools for this repair:
- Fuel line quick-disconnect tool set
- Ratchet
- 8mm socket
- 10mm socket
- 13mm socket
- 15mm socket
- Torque wrench
- Floor jack rated 3-ton minimum
- Jack stands rated for truck weight
- Wood block
- Fuel-safe drain pan
- Trim removal tool
- Brass punch
- Hammer
- Safety glasses
- Nitrile gloves
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Fuel pump module - Qty: 1
- Fuel pump module seal - Qty: 1
- Fuel tank strap bolts - Qty: 2
- Fuel line O-rings - Qty: 1 set
- Fuel filter - Qty: 1
- Fuel pump relay - Qty: 1
- Fuel injector/fuel system cleaner - Qty: 1
📋 Before You Begin
- Park on level ground and set the parking brake.
- Run the fuel level low if possible. Less fuel makes this much safer.
- Disconnect the negative battery cable before touching the fuel system.
- Relieve fuel pressure at the fuel rail service port before disconnecting lines.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Relieve fuel pressure and disconnect power
- Use the fuel line quick-disconnect tool set and a safe container to bleed off fuel pressure carefully at the service connection.
- Disconnect the negative battery cable using a 10mm socket.
- Keep a rag ready for small fuel spills.
Step 2: Raise and support the truck
- Use the floor jack to lift the truck.
- Place it securely on jack stands.
- Make sure the rear of the truck is stable before going underneath.
Step 3: Lower the fuel tank enough to access the module
- Use a 15mm socket to remove the fuel tank strap bolts.
- Support the tank with the floor jack and a wood block.
- Lower the tank slowly.
- Disconnect the filler neck, vent hose, EVAP lines, and fuel pump connector as they become accessible.
- Torque to 40 Nm (30 ft-lbs) on installation for the fuel tank strap bolts.
Step 4: Remove the fuel pump module
- Clean the top of the tank first so dirt does not fall inside.
- Use a brass punch and hammer to carefully loosen the lock ring.
- Lift the fuel pump module straight out of the tank.
- Remove the old seal and clean the sealing surface.
- Do not use steel tools on the tank flange.
Step 5: Install the new fuel pump module
- Install the new fuel pump module seal on the tank.
- Lower the new fuel pump module into place in the same orientation as the old one.
- Install and tighten the lock ring securely with the brass punch and hammer until fully seated.
- Reconnect the electrical connector and fuel lines.
- Check that the seal stays in its groove.
Step 6: Raise the tank and reconnect everything
- Use the floor jack to raise the tank back into position.
- Reconnect the filler neck, vent hose, EVAP lines, and fuel pump connector.
- Install the tank strap bolts with the 15mm socket.
- Torque to 40 Nm (30 ft-lbs).
Step 7: Reconnect power and prime the system
- Reconnect the negative battery cable with a 10mm socket.
- Turn the key to ON for 2-3 seconds, then OFF.
- Repeat this 3 times to prime the fuel system.
- Check carefully for fuel leaks at the tank and lines.
Step 8: Start and verify operation
- Start the engine using the ignition key.
- Let it idle and inspect again for leaks.
- Confirm normal fuel pressure and smooth running.
✅ After Repair
- Inspect the tank area one more time after a short test drive.
- Recheck for fuel smell or any wet spots under the truck.
- If the engine cranks long or stalls, cycle the key again to re-prime the system.
- If a check engine light stays on, scan for fuel system codes.
💰 DIY vs Shop Cost
Shop Cost: $900-$1,600 (parts + labor)
DIY Cost: $250-$550 (parts only)
You Save: $650-$1,050 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3-5 hours.
🎯 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.








