🔧 RX350 - Fuel Pump Replacement

On your RX350, the fuel pump sits inside the fuel tank as a pump/module assembly. The job is usually done from inside the cabin under the rear seat through an access cover, so you normally 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 very well-ventilated area—gas fumes are flammable.
• 🧤 No smoking, no hot lights, no grinding/sparks near the car.
• 🧿 Wear safety glasses—fuel can spray when lines are opened.
• 🔋 Disconnect the negative battery cable before opening the fuel system.
• 🧻 Keep rags ready and clean spills immediately; dispose of rags safely.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3/8" drive ratchet
• 3" extension (3/8" drive)
• Torque wrench (5–80 Nm range)
• Trim removal tool set
• Small flathead screwdriver
• Pick tool
• Fuel line disconnect tool set (quick-connect) (specialty)
• Fuel pump lock ring wrench (specialty)
• Brass drift punch
• Small hammer
• Needle-nose pliers
• Shop towels
• Catch pan
• Nitrile gloves
• Safety glasses
• Fire extinguisher (Class B)

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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 tank seal/O-ring - Qty: 1
• Fuel line O-rings (if applicable) - Qty: 1

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Run the fuel level low if you can—less fuel smell and less spill risk.
• Relieve fuel pressure before disconnecting lines (steps below).
• Open the fuel door and loosen the gas cap to release tank vapor pressure.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Relieve fuel pressure

• Open the hood.
• Open the engine-bay fuse/relay box (use a small flathead screwdriver if needed).
• Remove the fuel pump/EFI relay or fuse (commonly labeled EFI or F/PMP) using needle-nose pliers.
• Start the engine and let it run until it stalls; crank for 2–3 seconds more.
• Turn the ignition OFF.

Step 2: Disconnect the battery

• Use a 10mm socket and 3/8" drive ratchet to loosen the negative battery terminal and remove it.
• Move the cable aside so it can’t spring back.

Step 3: Remove the rear seat cushion

• From the rear passenger area, use a trim removal tool set to help release the seat cushion clips.
• Pull up firmly at the front edge of the seat cushion (it’s held by pop-clips).
• Lift the cushion out and set it aside.
• Tip: Pull straight up; don’t pry the carpet.

Step 4: Open the fuel pump access cover

• Locate the service/access cover in the floor under the seat area.
• Use a trim removal tool set and small flathead screwdriver to remove any clips or butyl sealer holding the cover.
• Lift the cover off and wipe dirt away using shop towels (keep debris out of the tank).

Step 5: Disconnect the electrical connector and fuel lines

• Unplug the pump/module electrical connector.
• Place shop towels and a catch pan under the line connections.
• For quick-connect fuel lines, use a pick tool to release the safety clip (if equipped), then use the fuel line disconnect tool set (quick-connect) (specialty) to separate the line.
• Cap/cover open lines with clean towels to reduce fumes and contamination.

Step 6: Remove the fuel pump lock ring

• Mark the module’s orientation to the tank with a small flathead screwdriver (a small reference mark helps alignment).
• Use a fuel pump lock ring wrench (specialty) to loosen and remove the lock ring.
• If you can’t fit the wrench, use a brass drift punch and small hammer to tap the lock ring loose (brass helps reduce spark risk).
• Torque to 68 Nm (50 ft-lbs) on installation (lock ring).

Step 7: Remove the pump/module assembly

• Carefully lift the assembly out of the tank opening.
• Angle it slowly to avoid bending the fuel level float arm.
• Let fuel drain into the tank, then set the module into a catch pan.

Step 8: Replace the tank seal/O-ring

• Remove the old tank seal/O-ring from the tank opening using a pick tool.
• Wipe the sealing surface clean with shop towels.
• Install the new seal/O-ring in the groove (don’t twist it).

Step 9: Install the new fuel pump module

• Lower the new module into the tank, keeping the float arm from snagging.
• Align it to your orientation mark.
• Install the lock ring and tighten with the fuel pump lock ring wrench (specialty).
• Torque to 68 Nm (50 ft-lbs) (lock ring).

Step 10: Reconnect fuel lines and electrical connector

• Reconnect the fuel lines until they click/lock.
• Reinstall any safety clips using needle-nose pliers.
• Reconnect the electrical connector until it clicks.

Step 11: Reinstall the access cover and rear seat cushion

• Reinstall the access cover and any clips using a trim removal tool set.
• Reinstall the rear seat cushion by lining up the clips and pressing down firmly.

Step 12: Restore power and prime the system

• Reconnect the negative battery cable using a 10mm socket and 3/8" drive ratchet.
• Reinstall the EFI/fuel pump relay/fuse using needle-nose pliers.
• Cycle ignition ON (engine OFF) for 5 seconds, then OFF for 5 seconds; repeat 3 times to prime.
• Start the engine and let it idle.

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✅ After Repair

• With the engine idling, check the access area for any fuel smell or wetness (leaks).
• Take a short test drive, then recheck for leaks.
• If a check engine light appears, scan and clear codes after confirming no leaks.

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💰 DIY vs Shop Cost

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

DIY Cost: $250-$800 (parts only)

You Save: $650-$800 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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