The Essential Guide to Facet Electric Fuel Pumps: Reliability, Replacement, and Performance

Facet electric fuel pumps represent a crucial, reliable, and often the best solution for consistent fuel delivery in classic vehicles, hot rods, motorcycles, and modern applications where dependable performance is paramount. Known for their robust construction, long service life, and straightforward installation, these pumps deliver the necessary fuel pressure and volume while resisting vapor lock and harsh environmental conditions. Choosing the correct Facet pump and installing it properly ensures years of trouble-free operation and optimal engine performance. Understanding the different models, their specifications, and application nuances is key to selecting the right pump for your specific vehicle and project needs.

Understanding the "Facet" Electric Fuel Pump. The term "Facet" refers to a brand historically renowned for manufacturing high-quality, durable, small-displacement roller-vane electric fuel pumps. While owned by Purflux Systems (part of the PSA Group), the Facet brand name remains synonymous with these specific, often cylindrical or cube-shaped fuel pumps. They operate using a unique, reliable vane-type mechanism driven by an electric motor, designed to provide steady fuel flow and pressure primarily for carbureted and low-pressure fuel-injected engines. Their popularity stems from consistent performance, resilience under demanding conditions like heat and vibration, and a reputation for longevity.

Core Operating Principle: Simple and Robust. Inside the pump casing, an electric motor spins an eccentric cam. Attached to this cam are multiple sliding vanes housed within a circular chamber. As the cam rotates, centrifugal force pushes these vanes outward against the chamber wall. The spinning cam creates expanding and contracting cavities between itself, the vanes, and the chamber wall. Fuel enters the pump through an inlet port located where the cavity is expanding. As the vanes rotate, they trap fuel within these pockets. The cam's eccentric shape forces the trapped fuel volume to decrease as the cavity moves towards the outlet port. This reduction in volume pressurizes the fuel, forcing it out through the discharge port to the engine. The constant rotation creates a continuous, pulsating flow. This roller-vane design contributes significantly to the pump's durability and resistance to damage from fuel contaminants compared to some impeller designs.

Primary Applications and Ideal Uses. Facet pumps excel in scenarios demanding reliable, low-to-moderate pressure fuel delivery:

  1. Classic Vehicles and Restoration: They are the go-to replacement for original mechanical pumps or worn-out old electric pumps in classic cars, trucks, and motorcycles, particularly carbureted models.
  2. Hot Rods and Custom Builds: Builders favor Facet pumps for their reliability, compact size (especially cube models), and ease of installation in custom fuel systems. They often serve as primary pumps or lift pumps feeding larger systems.
  3. Motorcycles and Powersports: Their compact dimensions make them suitable for motorcycles, ATVs, and other recreational vehicles needing supplemental fuel pressure or replacing OEM units.
  4. Low-Pressure Fuel Injection (TBI/TBI): Specific Facet models are designed to handle the pressure requirements of throttle body fuel injection systems (typically around 15 PSI).
  5. Auxiliary/Lift Pumps: Used in diesel or complex EFI systems to supply fuel from the tank to a higher-pressure primary injection pump.
  6. Aircraft and Marine: Certifications exist for specialized Facet pumps in aviation and marine environments, testament to their robust design.

Key Specifications: Choosing the Right Model. Selecting the appropriate pump requires matching pump specifications to engine demands:

  • Flow Rate: Measured in Gallons Per Hour (GPH) or Liters Per Hour (LPH). Essential to match engine fuel consumption needs. A typical small-block V8 carbureted engine might need 30-40 GPH at wide-open throttle. Under-pumping causes fuel starvation, oversizing is inefficient but generally safe.
  • Operating Pressure: Measured in Pounds per Square Inch (PSI) or Bar. Critical distinction:
    • Low Pressure (PSI): 2.5 - 4 PSI models are standard for carbureted engines.
    • Moderate Pressure (PSI): Models like the "Gold-Flo Cube" reach ~7 PSI, suitable for higher-demand carbureted engines or some alcohol fuels.
    • Electronic Fuel Injection: "Silver-Flo" cubes push 15 PSI, designed specifically for GM TBI systems and similar low-pressure EFI. Facet pumps are NOT suitable for high-pressure port injection systems (typically 35-80 PSI).
  • Voltage: Most automotive Facet pumps are rated for a nominal 12 Volts DC. Actual operating voltage should stay within 10-15V for optimal life. Dedicated 24V models exist for commercial/truck use.
  • Current Draw: Specified in Amps (A). Important for selecting the correct gauge wire and fuse size (typically 10A or less for common cubes/cylinders).
  • Inlet/Outlet Size: Common sizes include -6 AN, 1/8 NPT, 5/16" barb, or 3/8" barb connections. Verify compatibility with existing fuel lines or plan adapters. Seals must be fuel compatible!
  • Mounting Orientation: While many cubes offer multi-directional mounting flexibility, cylinder pumps typically have recommended orientations. Always confirm mounting requirements per the specific pump model.

Common Facet Models Explained. Distinguishing between the common shapes and series is vital:

  • Cylindrical "Posi-Flow" Pumps: The classic silver cylinders (e.g., 40105, 40162). Known for exceptional durability and long life.
    • Standard Flow (40105 equivalent): Typically flow ~30 GPH at low pressure (3-4 PSI). Ideal for most carbureted 4 & 6 cylinder engines and smaller V8s.
    • High Flow (40162 equivalent): Flow up to 35-40 GPH at low pressure. Suitable for high-performance carbureted V8s or engines with higher fuel demands.
    • Pressure Spec: Generally low-pressure (2.5-4.5 PSI).
  • "Cube" Style Pumps: Modern, compact rectangular shape (e.g., "Gold-Flo," "Silver-Flo"). Offer mounting flexibility.
    • Gold-Flo: Polished gold housing. Flow rates vary by part number (e.g., 476091 ~28 GPH, 476081 ~47 GPH). Higher pressure capability (~7 PSI max) than low-pressure cylinders. Suitable for demanding carbs or mild alky.
    • Silver-Flo: Designed for low-pressure EFI (TBI). Pushes ~15 PSI. Flow rates typically sufficient for V6/V8 TBI applications (e.g., 476133 ~40 GPH @ 15 PSI). Crucial: Not for high-pressure EFI.

Genuine Facet vs. Aftermarket Copies. This is a critical consideration:

  • Genuine Facet Pumps: Manufactured to strict quality control standards using proven materials. Consistently deliver rated performance and lifespan (often 10+ years). Best choice for reliability. Typically cost more.
  • Aftermarket Copies: Widely available at lower cost. Quality varies dramatically – from acceptable to extremely poor. Common issues include: lower flow/pressure than advertised, premature failure (months), diaphragm/vane materials incompatible with modern fuels (ethanol causes degradation), excessive noise, electrical connector failure. Use copies at your own risk; genuine is recommended for critical applications.

Correct Installation: Safety and Performance. Improper installation is a prime cause of fuel pump failure and safety hazards.

  1. Safety First: Disconnect battery negative terminal. Work in well-ventilated area away from sparks/flames. Have a fire extinguisher rated for fuel/electrical fires nearby.
  2. Mounting Location:
    • Below Tank Level: Essential! These pumps push well but pull poorly. Mount the pump lower than the bottom of the fuel tank so gravity feeds fuel to the pump inlet. Mounting level with or above the tank causes starvation.
    • Cool and Protected: Mount away from direct exhaust heat, moving suspension parts, and road debris. Heat drastically shortens pump life.
    • Secure: Use the mounting bracket or appropriate hardware to prevent vibration. Rubber isolation mounts are recommended.
  3. Wiring Correctly:
    • Circuit Protection: Install an in-line fuse holder rated for the pump's current draw (e.g., 7.5A or 10A) within ~12" of the power source connection. Use an automatic reset circuit breaker for added convenience if compatible.
    • Relay Mandatory: Never connect the pump directly to an ignition switch! Use a properly rated automotive relay. Connect:
      • Terminal 30: To Battery Positive (+12V fused at source near battery).
      • Terminal 85: To Chassis Ground.
      • Terminal 86: To Ignition Switch "ON" power source (provides relay trigger).
      • Terminal 87: To the fuel pump positive wire.
    • Grounding: Ensure a clean, bare-metal chassis ground connection for the pump's ground wire. Scrape paint, use star washer. Poor ground = poor performance/failure.
    • Wire Gauge: Use wire heavy enough for the current draw and distance (typically 14 AWG min. for power/ground over short runs, thicker for longer runs).
  4. Plumbing Connections:
    • Use Fuel Hose: ONLY use SAE J30R9 rated hose for gasoline (or SAE J30R14 for high-percentage ethanol). Standard heater hose disintegrates quickly. Replace old hoses.
    • Hose Clamps: Use proper screw-type fuel hose clamps at all barbed connections. Oetiker clamps are superior if applied correctly. "Fuel Injection" hose requires FI-rated clamps.
    • Avoid Restrictions: Ensure inlet hose is not kinked or undersized. Any restriction here starves the pump. A minimum 5/16" ID hose is common; larger for high-flow.
    • Direction: Confirm inlet and outlet ports (usually marked). Reversing severely damages vanes. Pre-filter inlet side plumbing strongly recommended.
  5. Pre-Filtering is Non-Negotiable: Install a robust inline fuel filter (100-150 micron) between the tank and the pump inlet. This traps debris before it enters the pump, protecting the vanes and preventing premature wear or catastrophic failure. Replace this filter periodically. Post-pump filtration (fine micron) is also recommended for carburetor jets/injectors.

Pre-Start Checks and Priming. Before hitting the key, perform vital checks:

  1. Triple-Check Wiring: Verify relay wiring is correct (especially grounds), fuse installed.
  2. Inspect Plumbing: Ensure no leaks at connections, hoses secured, inlet not restricted.
  3. Prime the Pump: Fill the pump and inlet line with fuel if possible. You can briefly jumper 12V directly to the pump (with fused jumper wires!) while observing for leaks and flow at the outlet hose (direct flow into a container, NOT onto engine!). This bypasses the ignition system for testing only. Listen for smooth operation without excessive noise. Disconnect jumper immediately after test. Alternatively, crank the engine briefly with the coil wire disconnected.
  4. Check for Leaks: After priming or cranking, carefully inspect EVERY connection from tank to pump to engine for any sign of fuel seepage. Tighten immediately if found.

Operational Sounds: Normal vs. Warning Signs. Facet pumps are generally quiet but audible:

  • Normal Sound: A steady, rhythmic clicking or buzzing sound. Level may vary slightly by model/mounting.
  • Warning Signs:
    • Increased Noise/Whine: Suggests cavitation or inlet restriction (insufficient fuel supply). Check filters, mounting height, tank pickup, plumbing.
    • Irregular Clicking/Pulsing: Indicates potential vane damage, internal blockage, or pump failure.
    • Screaming/Grinding: Severe internal damage or imminent failure. Shut down immediately.
    • Intermittent Operation: Often points to electrical issues: poor ground, failing relay, damaged wiring connection, or a pump internal electrical fault.
    • Sudden Silence (Pump Stopped): Blown fuse (check for short), failed relay, wiring disconnect, or pump motor burned out.

Troubleshooting Common Problems. Methodical diagnosis is key:

  • Pump Doesn't Run:
    • Check battery voltage at pump terminals when ignition is ON. Check fuse/circuit breaker. Verify relay function (listen for click, swap with known good). Check all ground points with a test light or multimeter. Test pump directly with fused jumper wires from battery. Replace pump if fails.
  • Pump Runs, But No/Insufficient Fuel:
    • Confirm sufficient fuel in tank!
    • Check for inlet restriction: blocked filter, kinked hose, plugged tank pickup sock.
    • Verify pump mounted below tank.
    • Check for leaks on inlet side plumbing drawing air.
    • Test pump flow rate by directing outlet into a container. Compare to specification. Replace if inadequate.
  • Pump Runs Loud/Noisy:
    • Check for inlet restriction (see above).
    • Ensure pump is mounted securely, vibration isolated if possible.
    • Verify correct voltage supply (low voltage can cause high current draw/overheating/noise). Check connections/relay/wire size.
  • Vapor Lock Symptoms:
    • Ensure pump is mounted away from exhaust heat sources.
    • Consider insulating fuel lines near heat.
    • Verify adequate flow rate/pressure for engine demand.
    • Check for excessive underhood temperatures.
  • Pressure Issues: Requires a fuel pressure gauge installed after the pump but before the carb/injector.
    • Low Pressure: Pump wear, incorrect pump type, fuel leak upstream of gauge, excessive restriction downstream (clogged filter, bent line), failing pressure regulator (if equipped).
    • No Pressure: Major leak, pump failure, severe inlet restriction. Stop immediately.

Maintenance and Longevity. Maximize pump life with simple steps:

  • Use Quality Fuel: Avoid old, degraded, or excessively contaminated gasoline.
  • Pre-Filter Maintenance: Regularly replace the inlet filter (100-150 micron) – every 12-24 months or per pump manufacturer/situation. Clean fuel = long pump life.
  • Post-Filter Maintenance: Replace finer engine inlet filters as per vehicle manual (10-40 micron).
  • Visual Inspections: Periodically check for fuel leaks, wiring chafing, loose connections, and mounting security.
  • Listen: Pay attention to changes in pump sound during operation. Early detection aids in prevention.
  • Fuel System Cleaning: Prevent excessive deposits in tank/lines, especially after periods of storage.

Why Facet Pumps Are a Smart Choice for Specific Applications. They stand out for reasons:

  • Proven Durability: Decades of reliable service in demanding conditions, especially cylinder models.
  • Vapor Lock Resistance: Mechanical displacement design (roller vane) generates less heat and moves vapor bubbles better than impeller types common in EFI lift pumps.
  • Robust Construction: Typically feature metal housings and internal components designed for longevity.
  • Clear Application Match: Widely documented and supported for classic and low-pressure fuel systems.
  • Consistent Performance: Delivers steady flow/pressure when correctly sized and installed.
  • Wide Availability: Genuine parts and replacement service components are readily accessible.

Selecting Your Perfect Facet Pump: Key Questions. Ask these before buying:

  1. Engine Type: Carbureted? Low-pressure TBI/TBI? Requires high-pressure EFI? (Critical for pressure selection!)
  2. Engine Demand: Horsepower rating? Displacement? High performance? Determines needed flow rate (GPH).
  3. Existing System: Replacing a failed pump? Matching specs? Adding a pump to a custom system?
  4. Mounting Constraints: Space available? Location relative to fuel tank (must be below)? Heat sources nearby? Influences cylinder vs. cube choice.
  5. Voltage: Vehicle 12V? 24V? System condition?
  6. Connection Types: Need barbs? AN fittings? NPT? Match existing plumbing or plan adapters.
  7. Genuine vs. Aftermarket: Value genuine Facet reliability? Willing to risk cheaper alternatives?
  8. Pre-Filter: How will you protect the pump inlet?

Beyond Basic Replacement: Special Considerations. Sometimes needs are unique:

  • Multiple Pumps: Using tandem pumps for redundancy or high-flow demands requires complex wiring and pressure relief configurations. Not plug-and-play.
  • Pulse Dampeners: While less common for Facets, dampeners smooth out inherent pressure pulses. Useful on sensitive carburetors or with long fuel lines.
  • Pump Wiring Modifications: Specific cube pumps may require reversing the inlet/outlet positions relative to electrical terminals for custom mounting. Verify terminal functions.
  • Ethanol-Blended Fuels (E10, E15): Genuine Facet pump materials are generally resistant to current ethanol blends when used correctly. Maintain filters! Highly corrosive blends require specialized system components.
  • Extended Storage: Fill the tank with fresh fuel treated with a stabilizer. Running the pump periodically isn't recommended.

Avoiding Critical Mistakes. Steer clear of these pitfalls:

  • Mounting Above Tank Level: Guaranteed starvation and pump destruction.
  • Omitting the Pre-Filter: Debris kills the pump fast.
  • Using Non-Fuel Rated Hose: Degrades, leaks, causes fire hazard.
  • Skipping the Relay: Burns out ignition switches or causes erratic operation.
  • Ignoring Electrical Grounds: Causes poor performance, overheating, failure.
  • Selecting Wrong Pressure: High pressure blows carb floats, low pressure starves EFI. Verify engine requirements.
  • Underestimating Flow Needs: Results in engine stumbling under load.
  • Mixing Inlet/Outlet Ports: Reversing destroys vanes.

Ensuring Optimal Performance Over Time. Beyond installation:

  • Monitor Fuel Pressure: Periodically check using a gauge, especially if performance issues arise. Mounting a permanent gauge is valuable diagnostic insurance.
  • Track Filter Condition: Note debris caught in filters – clues to tank condition.
  • Preventative Replacement: Consider replacing an older Facet cylinder pump (15+ years) proactively in a critical-use vehicle, even if still running. Carry a spare on long trips. Cube pumps generally have shorter expected lifespans but still offer reliability.

The Facet Advantage in Specific Market Niches.

  • Hot Rod Community: Reliability and compactness (cubes) win over complex aftermarket alternatives needing controllers. Gold-Flo cubes offer a sweet spot.
  • Vintage Restoration: Cylindrical pumps maintain period-correct aesthetics for many classics alongside modern performance and reliability. 40105 is a classic.
  • Budget Builds: While not the absolute cheapest, genuine Facet pumps offer unmatched value and longevity compared to low-tier alternatives, reducing costly rework and roadside failures.
  • Demanding Environments: Their vapor resistance and mechanical robustness make them preferred for aircraft auxiliary use, marine environments (with certified models), and dusty off-road conditions when properly protected.

Conclusion: Making the Right Fuel Pump Decision. For applications requiring durable, reliable, and efficient fuel delivery in the low-to-moderate pressure range, genuine Facet electric fuel pumps offer a compelling solution. Understanding the different models – cylinder versus cube, genuine versus copy, flow rates, and especially pressure ratings – is fundamental to success. Correct installation, centered on safety, proper mounting height, robust electrical wiring with a relay, and meticulous plumbing including a mandatory inlet filter, transforms a quality pump into a long-term asset. By respecting these principles and performing sensible maintenance, your Facet pump becomes an indispensable and trustworthy component of your vehicle's fuel system, ensuring consistent power and performance mile after mile.

Back to blog