The Complete Guide to the Filter-Fuel Tank Part Number 42072AE00A: Function, Fitment & Replacement

The filter-fuel tank assembly with part number 42072AE00A is an integrated OEM component designed primarily for specific Mitsubishi Fuso commercial truck models. Replacing this unit correctly is essential for ensuring optimal fuel delivery, protecting the engine injection system, and maintaining vehicle reliability under demanding operating conditions.

This comprehensive guide details everything you need to know about this specific part: what it does, where it fits, how to identify problems, how to replace it, and where to source reliable replacements. Understanding this critical component prevents costly repairs and downtime.

Understanding the Filter-Fuel Tank Assembly (42072AE00A)

Unlike systems with separate fuel filters, part number 42072AE00A refers to a specific assembly that integrates the fuel filter directly into the fuel tank module or housing. This design offers several advantages:

  • Space Saving: Consolidates components within the tank, optimizing engine bay space. Important in large commercial vehicles.
  • Simplified Plumbing: Reduces external fuel lines and potential leak points between the tank and the filter.
  • Priming Ease: Often incorporates check valves and features designed to aid in priming the fuel system after service.
  • Water Separation: Typically includes a water-in-fuel (WIF) sensor and a bowl or chamber for collecting and draining separated water from the fuel.
  • Integrated Filter: Contains the actual filtration element designed to trap contaminants before they reach the engine's sensitive fuel injection pump and injectors.

The entire assembly is submerged in the fuel within the tank, requiring specific materials and construction to handle prolonged exposure to diesel fuel. It is not an external spin-on or cartridge filter housing.

Primary Vehicle Fitment for 42072AE00A

This part number is a genuine OEM Mitsubishi Fuso component. Its primary fitment is confirmed for the following Mitsubishi Fuso commercial truck models and engine series:

  • Mitsubishi Fuso Canter/FE/FG Series (Specific Generations):
    • 2000s-era models equipped with the 4M5 engine series (Not exhaustive - always verify).
    • Later models transitioning towards the "Great" series may use different assemblies.
  • Specific Engine Applications:
    • 4M51-T Turbo Diesel Engines (Various power ratings).
    • 4M50-T Turbo Diesel Engines (Various power ratings).

Crucial Pre-Purchase & Installation Check: Vehicle model year, specific engine code (often found on the engine block or VIN plate), and existing part numbers are essential for confirmation. While 42072AE00A supersedes some older numbers, it does not fit all Canter models or newer Fuso trucks like the Canter "Great". Always cross-reference before purchase.

The Critical Role of the Integrated Fuel Tank Filter

The filter within the 42072AE00A assembly performs the vital first stage of fuel filtration. Diesel fuel, despite refinements and fuel station filtration, inevitably contains microscopic contaminants. These include:

  • Particulate Matter: Dust, dirt, rust from tanks, manufacturing debris.
  • Water: Condensation in tanks, contamination during fueling, phase separation in biodiesel blends.

Failure to remove these contaminants leads to:

  1. Injector Nozzle Damage: Small particles act like sandpaper, eroding precise injector tips, causing poor spray patterns, reduced power, increased smoke, and rough idle.
  2. Fuel Pump Wear: High-pressure pumps rely on fuel for lubrication. Particles cause premature wear to plungers and barrels.
  3. Water Damage: Water causes internal rust within fuel system components. Even worse, in extremely cold temperatures, water in fuel can freeze, blocking fuel flow entirely. Water can also promote microbial growth ("diesel bug") which clogs filters and systems.
  4. System Blockages: Buildup of contaminants and microbial slime can restrict fuel flow, leading to power loss and stalling.

The integrated filter in the 42072AE00A assembly is the primary defense against these issues, protecting the much more expensive downstream fuel system components.

Symptoms of a Failing or Clogged Filter-Fuel Tank Assembly

Problems associated with a failing 42072AE00A assembly often manifest as engine performance issues directly tied to restricted fuel flow or contamination bypass:

  1. Loss of Power / Reduced Performance: Especially noticeable under load or acceleration when fuel demand is highest. Caused by insufficient fuel flow due to a blocked filter or restricted passages in the assembly.
  2. Hard Starting / Long Cranking Times: Difficulty building sufficient fuel pressure in the injection system after the vehicle has been sitting (e.g., overnight).
  3. Engine Stalling: Sudden engine shutdown, often intermittent initially, becoming more frequent. This happens when fuel flow becomes severely restricted. Stalling might occur at idle, low speed, or under load.
  4. Engine Misfires / Rough Idling: Unstable engine operation caused by uneven fuel delivery to cylinders.
  5. Illuminated Check Engine Light (CEL) / Malfunction Indicator Lamp (MIL): The Engine Control Unit (ECU) detects fuel pressure issues or injector performance problems and stores related diagnostic trouble codes (DTCs).
  6. Illuminated Water-In-Fuel (WIF) Warning Light (If Applicable): If water accumulates in the separator bowl and isn't drained, the sensor will trigger the warning light. This signifies water is present, not necessarily that the assembly is broken, unless draining doesn't resolve it.
  7. Visible Fuel Contamination: Rarely directly observable on this internal assembly, but opening it during replacement might reveal heavy sediment, sludge, or water in the housing.
  8. Increased Fuel Consumption: A clogged filter forces the fuel pump to work harder, potentially increasing parasitic load on the engine.
  9. Black Exhaust Smoke: Unburned fuel due to poor atomization from damaged injectors or incomplete combustion due to fuel starvation.

When to Replace the Filter-Fuel Tank Assembly (42072AE00A)

Replacement is not solely based on mileage, but should consider:

  1. OEM Recommended Service Intervals: Mitsubishi Fuso specifies a replacement interval for the filter element within the assembly (e.g., 15,000 miles, 30,000 miles). Replace the entire assembly at the specified interval or sooner if symptoms arise. Note: Some assemblies allow separate filter element changes; 42072AE00A is an integrated assembly unit.
  2. Presence of Symptoms: Experiencing any of the symptoms listed above strongly suggests inspection and likely replacement, especially if filter age/mileage is unknown.
  3. After Major Fuel System Service: If injectors or the pump have failed due to contamination, replacing the filter assembly is mandatory to prevent rapid recurrence.
  4. After Fuel Contamination Event: If the vehicle has run on known-bad fuel or a large amount of water has entered the tank.
  5. Preventive Maintenance: For high-usage vehicles, replacing proactively at set intervals reduces the risk of unexpected breakdowns.

Step-by-Step Replacement Guide: Filter-Fuel Tank Assembly 42072AE00A

Warning: Fuel system work requires care. Diesel fuel under pressure is dangerous. Ensure work is done in a well-ventilated area away from sparks or flames. Wear safety glasses and gloves. Relieve fuel system pressure if applicable. This guide provides an overview; consult the vehicle's specific service manual for detailed procedures and safety precautions.

Tools Needed:

  • New Filter-Fuel Tank Assembly (42072AE00A)
  • New sealing rings/gaskets (usually supplied with assembly)
  • Hand tools (Sockets, wrenches, screwdrivers per model)
  • Fuel line disconnect tools (required for common fuel line connections)
  • Fuel-safe container
  • Shop rags / Absorbent pads
  • Torque wrench
  • Safety glasses & gloves

Procedure Overview:

  1. Safety First: Disconnect the vehicle's negative battery cable.
  2. Locate Fuel Tank & Sender Unit: Access the top of the fuel tank. This usually involves raising the vehicle safely on a lift or jack stands, or removing the truck bed/access panel. Identify the fuel sender unit/pump access plate on the top of the tank. This plate houses the electrical connector, fuel lines, and the assembly itself.
  3. Relieve Fuel Pressure (If Applicable): Refer to the service manual. Some systems require opening a Schrader valve on the high-pressure fuel rail, others rely on depressurizing via the fuel pump relay.
  4. Clean the Area: Thoroughly clean around the sender unit/pump mounting plate. Prevent dirt from falling into the tank when opened.
  5. Disconnect Electrical Connector & Fuel Lines:
    • Unplug the main electrical connector for the pump/sender assembly.
    • Identify fuel feed and return lines. Use the correct disconnect tool for the quick-connect fittings to detach fuel lines without damage. Have rags/container ready for minor fuel spillage.
    • Note: If the WIF sensor is separate, disconnect it.
  6. Remove Mounting Ring/Bolts: Remove the locking ring (often requiring a special tool or large drift punch and hammer) or retaining bolts securing the sender unit assembly to the tank.
  7. Extract the Old Assembly: Carefully lift the entire sender/pump/filter assembly straight out of the tank. Avoid damaging the fuel level float arm. Note its orientation. Allow fuel trapped in the assembly to drain back into the tank as much as possible. Wipe excess fuel.
  8. Prepare the New Assembly (42072AE00A):
    • Compare the new assembly to the old one carefully. Ensure identical design.
    • Verify new sealing rings/gaskets are correct and undamaged. Lubricate rubber seals with clean diesel fuel only (Do NOT use petroleum jelly/grease).
  9. Install the New Assembly:
    • Carefully lower the new 42072AE00A assembly into the tank, aligning it exactly as the old unit was positioned.
    • Replace the locking ring or retaining bolts. Torque to specification if bolts are used. Tighten the locking ring securely and evenly.
  10. Reconnect Fuel Lines & Electrical: Push fuel line connectors onto their fittings until they click securely. Reconnect the electrical connector. Reconnect any WIF sensor wiring.
  11. Reconnect Battery: Reattach the negative battery cable.
  12. Prime the System:
    • Many systems require priming after filter replacement. Turn the ignition key to the "ON" position for several seconds (do not start). Listen for the fuel pump running. Repeat 2-3 times. This fills the filter and pressurizes the low-pressure side.
    • Some systems require activating the pump via diagnostic tools or holding the accelerator pedal.
  13. Check for Leaks: Before starting the engine, double-check all connections. After priming, visually inspect all fuel line connections and the assembly mounting for leaks.
  14. Start Engine & Verify Operation: Start the engine. It might crank slightly longer than usual. Idle should stabilize. Check for leaks again while the engine runs. Verify no warning lights remain on (except possibly 'Service' lights that need resetting). Perform a test drive to ensure full power and no stalling.
  15. Clear DTCs: Use an OBD-II scanner to clear any stored fuel system trouble codes after successful replacement.

Choosing a Replacement: OEM vs. Aftermarket vs. Counterfeit

Selecting the right 42072AE00A replacement is critical for reliability:

  1. Genuine OEM (Mitsubishi Fuso):
    • Pros: Guaranteed fitment, manufactured to exact specifications, reliable materials and filtration media, full warranty support.
    • Cons: Highest initial cost.
  2. High-Quality Aftermarket:
    • Pros: Significantly lower cost than OEM, readily available. Reputable brands meet or exceed OEM specs.
    • Cons: Requires thorough research to find a truly reliable brand (see below). Potential for fitment variations.
  3. Budget Aftermarket / Unknown Brands:
    • Pros: Very low cost.
    • Cons: Significantly higher risk of poor quality - inferior filter media (less filtration efficiency, premature clogging), substandard materials (plastics cracking, seals leaking), poor fitment, missing critical components (e.g., WIF sensor). Avoid these.
  4. Counterfeit Parts:
    • Pros: None.
    • Cons: Packaging made to look like OEM but contains very low-quality parts. Severe risk to engine health. Source only from highly reputable suppliers.

Identifying Reputable Suppliers:

  • Established Parts Suppliers: Look for large, well-known commercial truck parts distributors with physical locations and strong reputations.
  • Authorized Dealerships: Order genuine OEM through Fuso dealers.
  • Reputable Online Retailers: Use established online platforms known for commercial truck parts and verify seller reviews.
  • Beware: Extremely low prices, unknown websites, and sellers without physical addresses are major red flags for counterfeits or low-quality parts.

Why Quality Matters for 42072AE00A:

A failure in this integrated assembly can have severe consequences:

  • Engine Damage: Bypassed contamination destroys injectors and pumps costing thousands to repair.
  • Vehicle Stalling: Creates dangerous driving situations, especially in traffic or hauling heavy loads.
  • Increased Downtime: Multiple repairs and diagnostics cost more than a quality part initially.
  • Fuel Leaks: Poorly made seals or housings can lead to fuel leaks, a serious fire hazard and environmental issue.

Investing in a genuine OEM or verified high-quality aftermarket unit pays off in long-term reliability and lower operating costs.

Maintaining Your Fuel System Beyond Filter Replacement

  1. Use Quality Fuel: Purchase fuel from reputable, high-volume stations. Consider branded premium diesel fuels with enhanced detergency and additives designed to clean injectors, control water, and improve lubricity.
  2. Monitor Water Separator: Drain the water collection bowl regularly as per the truck's manual or whenever the WIF light illuminates. Never let water accumulate.
  3. Biodiesel Considerations: If using biodiesel blends (especially above B5), be aware they attract more water and can degrade certain elastomers faster. Increase inspection frequency. Ensure the assembly is rated for the blend used.
  4. Fuel Additives (Judicious Use): Some diesel additives can help remove water, prevent microbial growth, clean injectors, and improve lubricity. Choose reputable brands and follow instructions carefully. Do not overuse.
  5. Prevent Tank Contamination: Ensure the fuel cap seal is in good condition. Keep fill nozzles clean. Avoid filling from questionable sources (e.g., questionable drums).

Cost Considerations for Filter-Fuel Tank Assembly 42072AE00A

  • Part Cost: Expect a significant range:
    • Genuine OEM: Highest cost.
    • Quality Aftermarket: Moderate cost savings compared to OEM.
    • Budget/Counterfeit: Very low cost (but high risk).
  • Labor Cost: Replacement is labor-intensive due to tank access requirements. Expect several hours of shop time. Costs vary widely by region and shop. Doing it yourself saves labor but requires tools, space, and skill.
  • Total vs. Future Costs: While a cheaper part saves money upfront, failure due to poor quality can lead to much higher costs for injectors, fuel pumps, and associated labor. Factor in potential downtime costs for commercial trucks.

Conclusion: Securing Reliability with the Correct 42072AE00A

The filter-fuel tank assembly part number 42072AE00A is a vital integrated component on specific Mitsubishi Fuso Canter trucks. Its primary role is safeguarding the engine by providing essential first-stage fuel filtration and water separation directly within the fuel tank. Recognizing symptoms of failure, understanding its specific fitment, and following correct replacement procedures are crucial for maintaining optimal vehicle performance, reliability, and longevity.

Always verify fitment details, prioritize genuine OEM or verified high-quality aftermarket assemblies from reputable suppliers, and adhere to precise installation techniques. Investing in the right 42072AE00A replacement and maintaining your overall fuel system protects your significant investment in the vehicle and prevents much more expensive repairs down the road. Regular maintenance and proactive replacement at service intervals are key to avoiding costly breakdowns.

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