🔧 4Runner - Fuel Pump Replacement

On your 4Runner, the fuel pump sits inside the fuel tank as part of an in-tank module. Most repairs are done through a service access cover under the rear seat, so you usually don’t have to drop the fuel tank.

Difficulty Level: Intermediate | Estimated Time: 2-4 hours

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⚠️ Safety & Precautions

• 🔥 Work outside or in a well-ventilated area; fuel vapors ignite easily.
• 🧯 Keep a Class B fire extinguisher nearby.
• ⚡ Disconnect the negative battery cable to prevent sparks.
• 🚭 No smoking, no shop lights with hot bulbs, no power tools near open fuel.
• 🧤 Wear gloves and safety glasses; fuel can irritate skin and eyes.
• ⛔ Relieve fuel pressure before disconnecting any fuel line.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Class B fire extinguisher
• 10mm socket
• 12mm socket
• 14mm socket
• 3/8" ratchet
• 3" extension
• Torque wrench (inch-pound)
• Torque wrench (foot-pound)
• Phillips screwdriver #2
• Trim panel removal tool
• Needle-nose pliers
• Pick tool
• Shop towels
• Drain pan
• Non-marring plastic scraper
• Fuel line disconnect tool set (specialty)
• Permanent marker

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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 gasket - Qty: 1
• New hose clamps - Qty: 2
• Dielectric grease (for electrical connectors) - Qty: 1

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📋 Before You Begin

• 🅿️ Park on level ground and set the parking brake.
• ⛽ Drive until the tank is near 1/4 full (less fuel = less mess and fumes).
• 🔌 Disconnect the negative battery cable using a 10mm socket.
• 🧠 Relieve fuel pressure before opening the fuel system (steps below).
• 🧼 Clean the area around the access cover so dirt can’t fall into the tank.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Relieve fuel pressure

• Open the hood and remove the engine cover if equipped.
• Pull the fuel pump relay or EFI fuse from the under-hood fuse/relay box (use needle-nose pliers carefully).
• Start the engine and let it run until it stalls.
• Crank the engine for 3 seconds two more times to bleed off remaining pressure.
• Turn the key OFF and reinstall the relay/fuse later during reassembly.

Step 2: Disconnect the battery

• Use a 10mm socket to loosen the negative battery terminal and remove it from the battery post.
• Tuck the cable aside so it can’t spring back.

Step 3: Remove the rear seat cushion (access the service cover)

• From the rear seat area, release the seat cushion latches (a firm pull up at the front edge of the cushion usually releases them).
• If your seat uses bolts, remove them with a 14mm socket.
• Lift the seat cushion out of the way.
• Tip: Take a photo before unplugging anything.

Step 4: Remove the fuel pump service cover

• Remove the service cover screws using a Phillips screwdriver #2 (or bolts using a 10mm socket, depending on fasteners).
• Use a trim panel removal tool to lift the cover without bending it.
• Clean dirt around the opening using shop towels.

Step 5: Disconnect electrical connector and fuel lines

• Unplug the fuel pump electrical connector (use a pick tool gently if the tab is stubborn).
• Place shop towels and a drain pan under the lines to catch fuel.
• Disconnect the quick-connect fuel line using the fuel line disconnect tool set (specialty).
• Pinch and slide any hose clamps using needle-nose pliers, then twist hoses off by hand (don’t pry hard on plastic fittings).

Step 6: Mark orientation and remove the fuel pump module

• Use a permanent marker to mark the module’s orientation to the tank (helps prevent a crooked seal).
• Remove the module retaining fasteners using a 10mm socket.
• Lift the module straight up slowly; angle it as needed to clear the float arm (fuel level sender).
• Pour any fuel in the module into the drain pan.

Step 7: Replace the tank seal (critical)

• Remove the old seal/O-ring from the tank opening using a pick tool.
• Clean the sealing surface with a non-marring plastic scraper and shop towels.
• Install the new seal/O-ring (do not reuse the old one).

Step 8: Install the new fuel pump module

• Lower the new module into the tank carefully, guiding the float arm in without bending it.
• Align your marker marks and seat the module evenly on the new seal.
• Install the retaining fasteners by hand first, then tighten evenly in a crisscross pattern using a 10mm socket.
• Torque to 5 N·m (44 in-lbs) using an inch-pound torque wrench.

Step 9: Reconnect fuel lines and electrical

• Reconnect the fuel quick-connect line until you hear/feel it click, then tug lightly to confirm it’s locked.
• Reinstall hoses and replace clamps as needed using needle-nose pliers.
• Add a tiny amount of dielectric grease to the connector seal (not the metal pins), then plug the connector back in.

Step 10: Reinstall the service cover and rear seat

• Reinstall the service cover using a Phillips screwdriver #2 (or 10mm socket if bolts).
• Reinstall the rear seat cushion and any bolts using a 14mm socket.
• Torque seat bolts to 39 N·m (29 ft-lbs) using a foot-pound torque wrench (if equipped).

Step 11: Restore power and prime the system

• Reconnect the negative battery cable using a 10mm socket.
• Turn the key to ON (not start) for 5 seconds, then OFF. Repeat 3 times to prime the fuel system.
• Start the engine and let it idle.

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✅ After Repair

• 👃 Sniff-check for fuel odor around the rear seat area and outside near the tank.
• 🔍 With the engine idling, inspect the fuel line connection for seepage (use a flashlight, not a hot work light).
• 🧾 Clear any stored codes if the check engine light stays on (a scan tool can help confirm fuel pressure-related codes are gone).
• 🚗 Take a short test drive, then recheck for leaks.

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💰 DIY vs Shop Cost

Shop Cost: $900-$1,500 (parts + labor)

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

You Save: $650-$850 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-4 hours.

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🎯 Ready to get started?

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