🔧 Yukon - Fuel Pump Replacement

The fuel pump on your Yukon is part of an in-tank fuel pump module. Replacing it typically means safely lowering the fuel tank, swapping the module, then reinstalling everything and checking carefully for leaks.

Assumption: Stock in-tank pump module (tank must be lowered; no interior access panel).

Difficulty Level: Advanced | Estimated Time: 3-6 hours

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⚠️ Safety & Precautions

• ⛽ Work outside or in a very well-ventilated area; fuel fumes ignite easily.
• 🔥 No smoking, no heaters, no drop lights with hot bulbs; use an LED work light.
• 🧯 Keep a Class B fire extinguisher nearby.
• 🧤 Wear safety glasses and fuel-resistant gloves; fuel can splash when lines disconnect.
• 🔋 Disconnect the negative battery cable before disconnecting any fuel lines.
• 🛑 Support the tank with a transmission jack; a full tank is heavy and unstable.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Fuel-resistant nitrile gloves
• Fire extinguisher (Class B)
• Wheel chocks
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Transmission jack (specialty)
• Metric socket set (8mm-21mm)
• 3/8" drive ratchet
• 1/2" drive breaker bar
• Torque wrench (10-200 ft-lbs range)
• Flat-blade screwdriver
• Trim clip removal tool
• Fuel line quick-disconnect tool set (3/8" and 1/2")
• Brass punch
• Dead-blow hammer
• Fuel pump lock ring tool (specialty)
• Drain pan (at least 3-gallon)
• Siphon pump (hand pump)
• Shop towels
• Marker paint pen
• OBD2 scan tool (optional)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Fuel pump module assembly - Qty: 1
• Fuel pump module seal/O-ring - Qty: 1
• Fuel tank strap bolts (recommended) - Qty: 2
• EVAP line retainer clips (as needed) - Qty: 1-3

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear tires.
• Run the fuel level as low as possible. Less fuel = much easier job.
• Relieve fuel pressure before opening the system (steps below).
• Plan how you’ll support the tank: a transmission jack is the safest option (it cradles the tank).
• Uncommon terms you’ll see: EVAP is the “fuel vapor” system; quick-connect lines use internal clips and need a disconnect tool.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect battery power

• Use an 10mm socket and ratchet to disconnect the negative battery cable and move it aside so it can’t spring back.

Step 2: Relieve fuel system pressure

• Open the fuel door and loosen the gas cap to vent tank vapor.
• Locate the underhood fuse/relay block and remove the fuel pump relay (use the fuse puller or needle-nose pliers if included in your kit).
• Start the engine and let it run until it stalls.
• Crank for 3 seconds once more to bleed off remaining pressure, then turn key OFF.

Step 3: Raise and support the vehicle

• Use a floor jack (rated 3-ton minimum) to lift the rear of the vehicle at the proper lift point.
• Set it securely on jack stands (rated 3-ton minimum).

Step 4: Remove shields/skid plate (if equipped)

• Use a metric socket set (typically 13mm or 15mm) with a ratchet to remove any fuel tank shield or skid plate fasteners.
• Set the shield aside.

Step 5: Reduce fuel weight (recommended)

• Use a siphon pump (hand pump) to remove fuel into approved fuel containers.
• Keep a drain pan and shop towels ready for spills.

Step 6: Support the fuel tank

• Position the transmission jack (specialty) under the center of the tank.
• Use a block of wood (optional) to spread load and prevent tank damage.

Step 7: Disconnect filler neck and vent connections

• At the filler neck area, use a flat-blade screwdriver to loosen hose clamps (if present).
• Carefully work the hoses off. Use shop towels to catch drips.

Step 8: Disconnect EVAP and electrical connectors at the tank

• Lower the tank slightly (1-3 inches) using the transmission jack to gain access on top.
• Disconnect the fuel pump module electrical connector by releasing the tab (use a trim clip removal tool or flat-blade screwdriver gently if needed).
• Disconnect EVAP vapor lines (use the fuel line quick-disconnect tool set if it’s a quick-connect style).

Step 9: Disconnect the fuel feed line

• Wrap the connection with a shop towel.
• Use the fuel line quick-disconnect tool (3/8" or 1/2" as required) to release the line, then pull it straight off.
• If it won’t release, re-seat and try again.

Step 10: Remove the tank straps

• Use a breaker bar and socket (typically 15mm) to remove the fuel tank strap bolts.
• Keep one hand stabilizing the straps while the tank stays supported by the transmission jack.
• Torque spec (reinstall): Torque to 25 Nm (18 ft-lbs)

Step 11: Lower and remove the fuel tank

• Slowly lower the tank with the transmission jack, checking continuously for any remaining connected lines.
• Once fully clear, slide the tank out from under the vehicle.

Step 12: Clean the pump module area

• Use shop towels to wipe dirt away from the top of the tank around the pump module.
• Dirt in the tank can ruin the new pump.

Step 13: Remove the lock ring and fuel pump module

• Mark the module orientation with a marker paint pen so the new one goes in the same way.
• Use a fuel pump lock ring tool (specialty) to rotate the lock ring counterclockwise and remove it.
• If needed, use a brass punch and dead-blow hammer to tap the ring carefully. (Brass helps reduce spark risk.)
• Lift the module out slowly, angling it to clear the fuel level float arm.
• Remove and discard the old seal/O-ring.

Step 14: Install the new seal and new fuel pump module

• Install the new fuel pump module seal/O-ring in the tank groove.
• Insert the new module in the same orientation as your marks.
• Reinstall the lock ring using the fuel pump lock ring tool (specialty) until it is fully seated against its stops.

Step 15: Reinstall the fuel tank

• Place the tank back onto the transmission jack and raise it close to position.
• Reconnect the top electrical connector and EVAP lines before the tank is fully up (use the trim clip removal tool as needed).
• Reconnect the fuel feed line until it clicks; tug lightly to confirm it’s locked.
• Install tank straps and hand-start bolts, then tighten with a ratchet and torque with a torque wrench.
• Torque spec: Torque to 25 Nm (18 ft-lbs)

Step 16: Reinstall shields/skid plate and lower the vehicle

• Reinstall the shield/skid plate using a socket set and ratchet.
• Raise slightly with the floor jack, remove jack stands, then lower fully.

Step 17: Restore power and prime the fuel system

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

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✅ After Repair

• With the engine idling, inspect under the vehicle for any fuel leaks at the tank lines and module area.
• Drive a short loop near home, then re-check for leaks.
• If a check-engine light appears, use an OBD2 scan tool to read codes (common causes are an EVAP connector not fully seated).

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💰 DIY vs Shop Cost

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

DIY Cost: $250-$700 (parts only)

You Save: $650-$900 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3-6 hours.

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