🔧 Colorado - Fuel Pump Module Replacement

On your Colorado, the electric fuel pump is part of the in-tank fuel pump module. Replacing it requires safely lowering the fuel tank, disconnecting the fuel lines and wiring, then swapping the pump module and seal.

Difficulty Level: Advanced | Estimated Time: 3-5 hours

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⚠️ Safety & Precautions

• 🔥 Gasoline vapors are highly flammable. Work outside or in a very well-ventilated area away from flames, heaters, cigarettes, and sparks.
• 🧯 Keep a Class B/C fire extinguisher nearby before opening the fuel system.
• 👀 Wear safety glasses and fuel-resistant gloves. Fuel can splash when lines are disconnected.
• 🔋 Disconnect the negative battery cable before working near the fuel tank wiring.
• ⛽ Run the fuel tank as close to empty as possible. A full tank is heavy and unsafe to lower.
• 🚫 Do not use power tools on the fuel pump lock ring. Sparks near fuel vapors are dangerous.
• 🧼 Clean dirt from the top of the fuel tank before opening it. Dirt inside the tank can damage the new pump.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 13mm socket
• 15mm socket
• 3/8-inch ratchet
• 3/8-inch extension set
• Torque wrench rated 10-100 ft-lbs
• Fuel line disconnect tool set (specialty)
• Fuel pump lock ring tool (specialty)
• Flat-blade screwdriver
• Plastic trim tool
• Needle-nose pliers
• Floor jack rated 3-ton minimum
• Jack stands rated 3-ton minimum
• Transmission jack or wide fuel tank support board
• Wheel chocks
• Shop towels
• Fuel-safe drain pan
• Brass punch
• Rubber mallet
• Safety glasses
• Fuel-resistant gloves
• Class B/C fire extinguisher

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Fuel pump module assembly - Qty: 1
• Fuel pump tank seal/O-ring - Qty: 1
• Fuel pump lock ring - Qty: 1
• Fuel line retaining clips - Qty: As needed
• EVAP line retaining clips - Qty: As needed
• Fuel system cleaner-safe shop towels - Qty: 1 pack

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📋 Before You Begin

• 🅿️ Park your Colorado on level ground, shift to Park, and set the parking brake.
• 🧱 Place wheel chocks in front of the front wheels.
• ⛽ Make sure the fuel tank is near empty. Less fuel means less weight and less spill risk.
• 🔋 Use a 10mm socket to disconnect the negative battery cable. Set it aside so it cannot touch the battery post.
• 🧯 Place a Class B/C fire extinguisher within reach.
• 📘 A fuel line disconnect tool releases spring-lock fuel fittings without breaking them.
• 📘 A fuel pump lock ring tool turns the large metal retaining ring that holds the pump in the tank.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Relieve Fuel Pressure

• Use a plastic trim tool to remove the underhood fuse box cover.
• Pull the fuel pump relay or fuel pump fuse using needle-nose pliers.
• Start the engine and let it run until it stalls. This uses up pressure in the fuel line.
• Crank the engine for 3-5 seconds more with the iginition key, then turn the key off.
• Use a 10mm socket to disconnect the negative battery cable if not already disconnected.
• Fuel may still drip.

Step 2: Raise and Support the Truck

• Use a floor jack rated 3-ton minimum to lift the rear of your Colorado at the proper rear frame lift point.
• Place jack stands rated 3-ton minimum under the frame rails.
• Lower the truck gently onto the jack stands.
• Shake the truck lightly by hand to confirm it is stable before going underneath.

Step 3: Support the Fuel Tank

• Place a transmission jack or floor jack with a wide support board under the fuel tank.
• Raise it just enough to support the tank. Do not crush the tank.
• Use shop towels and a fuel-safe drain pan under the fuel line area.

Step 4: Disconnect the Filler Neck and Vent Hoses

• Use a flat-blade screwdriver or 8mm nut driver if equipped to loosen the filler hose clamp at the tank.
• Use needle-nose pliers to release spring clamps on the smaller vent hose if equipped.
• Twist the hoses gently by hand to break them loose, then slide them off the tank fittings.
• Twist first, then pull.

Step 5: Disconnect EVAP and Electrical Connectors

• Use a plastic trim tool to lift the locking tabs on EVAP vapor line connectors.
• Press the connector tabs by hand and pull the EVAP lines straight off.
• Use a flat-blade screwdriver only if needed to gently unlock electrical connector safety locks.
• Disconnect the fuel pump electrical connector by pressing the tab and pulling straight back.

Step 6: Disconnect the Fuel Feed Line

• Place shop towels around the fuel line connection.
• Use the correct size fuel line disconnect tool from the fuel line disconnect tool set to release the fitting.
• Push the line inward first, insert the disconnect tool, then pull the line straight off.
• Catch any fuel in a fuel-safe drain pan.
• Do not pry plastic fittings.

Step 7: Remove the Fuel Tank Straps

• Use a 15mm socket, 3/8-inch ratchet, and extension to remove the fuel tank strap bolts.
• Keep one hand on the tank or jack while removing the last bolt.
• Lower the tank a few inches with the jack and check for any remaining lines or wiring.
• If anything is still attached, stop and disconnect it using the correct tool before lowering farther.

Step 8: Lower the Fuel Tank

• Use the floor jack or transmission jack to slowly lower the tank to the ground.
• Keep the tank level so remaining fuel does not spill out.
• Slide the tank out from under your Colorado.

Step 9: Clean the Pump Area

• Use shop towels to wipe dirt from the top of the fuel tank around the pump module.
• Use a soft brush if needed, but do not blow dirt into the tank opening.
• Mark the pump position with a marker or small piece of tape so the new pump faces the same way.

Step 10: Remove the Fuel Pump Lock Ring

• Use a fuel pump lock ring tool to turn the lock ring counterclockwise.
• If the lock ring is stuck, use a brass punch and rubber mallet to tap the lock ring tabs counterclockwise.
• Do not use a steel punch because it can create sparks.
• Lift off the lock ring and set it aside if it is being reused, though replacement is recommended.

Step 11: Remove the Old Fuel Pump Module

• Lift the fuel pump module straight up by hand.
• Tilt it slightly to clear the fuel level float arm. The float arm measures the fuel level.
• Let fuel drain from the module into the tank for a few seconds.
• Remove the old tank seal/O-ring by hand and discard it.

Step 12: Install the New Seal and Pump Module

• Wipe the tank sealing surface clean with shop towels.
• Install the new fuel pump tank seal/O-ring by hand into the groove on the tank.
• Lower the new fuel pump module into the tank carefully.
• Make sure the fuel level float arm does not bend or catch.
• Align the new pump module with the position mark made earlier.

Step 13: Install the Lock Ring

• Install the new fuel pump lock ring by hand until it sits evenly.
• Use the fuel pump lock ring tool to turn the lock ring clockwise until fully seated against the stops.
• If using a brass punch and rubber mallet, tap gently and evenly around the ring.
• Confirm the pump module is flat and the seal is not pinched.

Step 14: Reinstall the Fuel Tank

• Slide the tank back under your Colorado.
• Use the transmission jack or floor jack with support board to raise the tank slowly.
• Reconnect any upper electrical connector, EVAP line, or fuel line that is easier to reach before the tank is fully raised.
• Push quick-connect fuel and EVAP lines on until they click.
• Gently tug each line by hand to verify it is locked.

Step 15: Reinstall the Fuel Tank Straps

• Position the tank straps by hand.
• Start the strap bolts by hand to avoid cross-threading.
• Use a 15mm socket and torque wrench to tighten the fuel tank strap bolts to Torque to 35 Nm (26 ft-lbs).

Step 16: Reconnect Filler Neck, Vent Hoses, and Wiring

• Slide the filler hose fully onto the tank neck by hand.
• Use a flat-blade screwdriver or 8mm nut driver to tighten the filler hose clamp snugly.
• Reconnect vent hoses and spring clamps using needle-nose pliers.
• Reconnect the fuel pump electrical connector until it clicks.
• Recheck that all lines are routed away from sharp edges and exhaust parts.

Step 17: Lower the Truck

• Use the floor jack to lift the rear slightly off the jack stands.
• Remove the jack stands by hand.
• Lower your Colorado slowly to the ground with the floor jack.

Step 18: Reconnect Battery and Prime the Fuel System

• Use a 10mm socket to reconnect the negative battery cable.
• Reinstall the fuel pump fuse or relay if removed.
• Turn the key to ON for 5 seconds without starting the engine.
• Turn the key OFF for 10 seconds.
• Repeat this ON/OFF cycle 3 times to fill the fuel lines.
• Priming helps prevent long cranking.

Step 19: Start and Inspect

• Start the engine and let it idle.
• Use a flashlight to inspect under the truck near the fuel tank and fuel lines.
• Look and smell for fuel leaks. Shut the engine off immediately if any leak appears.
• Do not drive until all leaks are fixed.

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✅ After Repair

• ✅ Let the engine idle for 2-3 minutes and confirm it runs smoothly.
• 🔍 Check the fuel gauge. If it reads incorrectly, the float arm may be stuck or bent.
• ⛽ Add several gallons of fuel, then recheck for leaks around the tank.
• 🚗 Take a short test drive close to home, then inspect again for fuel smell or dripping.
• 🧠 If a check engine light is on, scan for codes related to fuel pressure, EVAP, or fuel level sensor.

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💰 DIY vs Shop Cost

Shop Cost: $750-$1,300 (parts + labor)

DIY Cost: $250-$600 (parts only)

You Save: $500-$700 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-4.0 hours.

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