04 Jeep Grand Cherokee Fuel Pump Replacement: A Complete DIY Guide

If your 2004 Jeep Grand Cherokee is struggling to start, losing power while driving, or making a whining noise from the fuel tank area, you likely need to replace the fuel pump. The fuel pump is an electric unit located inside the fuel tank, and for the 2004 model year, the only proper way to service it is to remove the fuel tank from the vehicle. This guide will walk you through the entire process step by step, from diagnosing the problem to installing the new pump and testing the system. The average cost for a professional replacement ranges from $962 to $1,135, with parts alone running around $591 and labor between $371 and $545. Doing it yourself will save you a significant amount of money, but you must follow all safety precautions carefully.

Symptoms of a Failing Fuel Pump

Before you start tearing things apart, make sure the fuel pump is actually the problem. Common signs of a failing fuel pump include:

  • Difficulty starting the engine – The engine cranks but won't fire up, or it takes many attempts to start.
  • Loss of power while driving – The vehicle feels sluggish, especially when accelerating or climbing hills.
  • Engine stalling – The engine suddenly dies, often at low speeds or while idling.
  • Whining noise from the fuel tank – A high-pitched hum or whine coming from the rear of the vehicle is a classic sign of pump wear.
  • Check Engine Light – A lean running condition can trigger the Check Engine Light and set diagnostic trouble codes.

If you experience any of these symptoms, the first step is to check the fuel pump fuse and relay. If the fuse is blown, replace it with one of the same amperage. If the fuse and relay are fine, check for power and ground at the pump itself. If there is power and ground but the pump doesn't run, the pump is faulty.

Safety First: What You Need to Know

Working on a fuel system is dangerous. Gasoline is highly flammable, and fuel vapors are explosive. Follow these precautions:

  • Work in a well-ventilated area – Preferably outdoors, away from open flames, pilot lights, and any source of ignition.
  • Disconnect the battery – Remove the negative battery cable before starting any work.
  • Relieve fuel system pressure – The fuel system is under constant pressure, even with the engine off. To relieve pressure, you can run the engine, then pull the fuel pump relay while the engine is running, and let the engine stall. Alternatively, with the engine off, you can press the Schrader valve on the fuel rail (if equipped) momentarily, capturing the small fuel spray that comes out with a rag.
  • Have a fire extinguisher nearby – Make sure it's rated for gasoline fires.
  • Wear safety glasses and gloves – Fuel can irritate your skin and eyes.
  • Do not smoke – This should go without saying, but smoking near a fuel system is extremely dangerous.

Tools and Parts You Will Need

Before you begin, gather the following tools and supplies:

  • Fuel pump kit – For the 2004 Jeep Grand Cherokee with a 4.0L or 4.7L engine, the complete fuel pump assembly (including the sending unit) is the recommended replacement part. Common OEM part numbers include 5012380AD, 5018056AC, and FG0918.
  • Floor jack and jack stands – To safely lift and support the vehicle.
  • Hydraulic jack or transmission jack – To support the fuel tank when lowering it.
  • Tool 9340 (fuel pump lock ring tool) – A special tool designed to remove the plastic lock ring on the fuel pump module. You can also use a brass punch and hammer as a non-sparking alternative.
  • ½ inch breaker bar – To drive the lock ring tool.
  • Socket set – 13mm, 15mm, 18mm, and 19mm sockets are common for this job.
  • Hose clamp pliers – For removing fuel line clamps.
  • Drain pan – To catch any fuel that spills.
  • Rags and shop towels
  • New O-ring or gasket – Most fuel pump kits come with a new rubber gasket for the fuel tank. Never reuse the old gasket, as it will almost certainly leak.
  • Rust penetrant – To help loosen stubborn bolts.

Step-by-Step Fuel Pump Replacement

Step 1: Prepare the Vehicle and Relieve Fuel Pressure

Park the vehicle on a firm, level surface and set the parking brake. Place wheel chocks behind the rear wheels for safety. Disconnect the negative battery cable. Relieve the fuel system pressure as described above. If the tank is full, siphon or drain as much fuel as possible to make the tank lighter and easier to handle.

Step 2: Raise the Vehicle and Access the Fuel Tank

Raise the rear of the vehicle using a floor jack and support it securely on jack stands. You need enough clearance to work under the vehicle comfortably. The fuel tank is located under the rear of the vehicle, behind the rear axle.

Step 3: Disconnect Fuel Lines and Electrical Connections

Locate the fuel filler hose and the vent hose on the side of the tank. Loosen the clamps and remove the hoses. Have a rag ready to catch any fuel that drips out. Underneath the vehicle, you will find the main electrical connector for the fuel pump and the fuel supply and return lines. Disconnect the electrical connector. For the fuel lines, use the correct quick-connect tool to disconnect the fittings. Be prepared for some fuel spillage.

Step 4: Support and Lower the Fuel Tank

Place a hydraulic jack or transmission jack under the fuel tank. Use a block of wood on the jack to distribute the weight and prevent damage to the tank. Remove the bolts that secure the fuel tank straps to the frame. Slowly lower the tank a few inches. You may find additional electrical connections or vapor lines on top of the tank that you couldn't see before; disconnect these before fully removing the tank.

Step 5: Remove the Fuel Pump Module

With the tank on a stable surface, you can now access the fuel pump module. It is held in place by a large, round plastic lock ring. Using the special tool 9340 and a ½ inch breaker bar, rotate the lock ring counter-clockwise to loosen it. The lock ring can be stubborn. If you don't have the special tool, use a brass punch and a hammer to gently tap the ring counter-clockwise to break it free. Brass is non-sparking, which is a critical safety precaution. Once the ring is off, carefully lift the entire fuel pump assembly out of the tank. Take note of the orientation of the pump and the float arm. Be careful not to bend the float arm on the fuel level sending unit.

Step 6: Install the New Fuel Pump

Before installing the new pump, clean the mating surface on the fuel tank thoroughly. Install the new rubber gasket that came with your fuel pump kit. Position the new fuel pump module into the opening in the fuel tank. Rotate the module until the indexing arrow at the top of the module is pointed toward the rear of the vehicle. Align the arrow to the tick mark on the top of the fuel tank. This step is critical to prevent the float and float rod assembly from contacting the sides of the fuel tank. Make sure the fitting on top of the fuel pump faces toward the driver's side. Hand-tighten the lock ring, then use your punch to gently tap it clockwise until it is snug. Tighten the lock ring to the manufacturer's specification, which is 55 ft-lbs (74 Nm) for the 1999-2004 models.

Step 7: Reinstall the Fuel Tank

Raise the fuel tank back into position. Reconnect all the top-side electrical and vapor lines that you noted earlier. Secure the tank with the straps and torque the strap bolts to the manufacturer's specification, which is typically around 40 ft-lbs. Over-tightening can damage the tank. Reconnect the main electrical connector and fuel lines underneath. Reconnect the filler hose and vent hose, and tighten the clamps.

Step 8: Prime the Fuel System and Test

Reconnect the negative battery cable. Before starting the engine, turn the key to the "on" position for a few seconds and then off, repeating this 2-3 times. This allows the new fuel pump to prime the system and build pressure, preventing a dry start. Start the engine and check meticulously for any fuel leaks around the pump module and line connections before driving. If the engine starts and runs smoothly, and there are no leaks, the job is complete.

Recommended Fuel Pump: KEMSO Brand

When it comes to replacing your fuel pump, choosing a high-quality product is essential for long-term reliability and performance. KEMSO offers a range of high-performance fuel pumps that are designed as direct OEM replacements for your 2004 Jeep Grand Cherokee. KEMSO fuel pumps are built with precision engineering to meet or exceed original equipment specifications, ensuring proper fuel pressure and delivery for your 4.0L or 4.7L engine. Every KEMSO fuel pump is backed by a lifetime warranty, giving you peace of mind that your investment is protected. Whether you are a DIY enthusiast or a professional mechanic, KEMSO provides a reliable, drop-in solution that simplifies the installation process.

To browse the full selection of KEMSO fuel pumps for your Jeep Grand Cherokee, visit their website at: https://www.kemsoracing.com/

Final Tips for a Successful Replacement

  • Replace the fuel filter at the same time – A clogged fuel filter can put extra strain on your new pump and shorten its lifespan. It is a cheap and easy part to replace while you have the system open.
  • Check the fuel pump relay and fuse – Even if you replace the pump, a faulty relay or fuse will prevent the new pump from running. Make sure the electrical system is in good condition.
  • Don't run the tank low on fuel – Repeatedly running the fuel tank low can cause the fuel pump to overheat and fail prematurely. Try to keep at least a quarter of a tank of fuel in the vehicle at all times.
  • Monitor the system after replacement – For the first few days after the replacement, keep an eye on the area around the fuel pump module for any signs of leaks. Listen for any unusual noises from the new pump.

Replacing the fuel pump on your 2004 Jeep Grand Cherokee is a challenging but rewarding DIY project. By following this guide carefully and using quality replacement parts, you can restore your vehicle's performance and reliability for many miles to come.

For more information on the best fuel pump for your Jeep Grand Cherokee, visit https://www.kemsoracing.com/


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