Diesel engines are known for their durability, torque, and efficiency, but their performance and longevity depend heavily on the quality of the fuel they receive. A high-quality fuel delivery system, such as the FASS Fuel System, ensures that diesel engines receive clean, pressurized fuel, reducing wear on critical components like fuel injectors and extending the life of the engine. However, the benefits of a FASS system are contingent on a precise and professional installation. This article provides a detailed, step-by-step guide to installing a FASS fuel pump system, based on official installation documentation and technical specifications.
Safety First: Pre-Installation Preparation and Critical Warnings
Before beginning the installation, it is essential to prioritize safety. FASS fuel systems operate under pressure and involve flammable materials, so proper precautions must be taken to prevent injury and equipment damage.
Disconnect Power Sources
Start by disconnecting the negative battery terminal. On diesel trucks, it is common to have multiple batteries, so all negative terminals should be disconnected to eliminate the risk of electrical shock or sparks. Ensure the disconnected cables are placed in a location where they cannot accidentally come into contact with the terminals.
Depressurize the Fuel System
Locate the factory fuel pressure test port, typically a Schrader valve found on the high-pressure fuel rail. Cover the port with a thick rag and use an appropriate tool to depress the valve core slowly. This releases any residual pressure in the system. Be prepared to capture any fuel that may spray out during this process. This step is critical—pressurized fuel can cause serious injury if not handled properly.
Installation Procedures: Mounting the FASS Pump Assembly
Once the system is depressurized and the power is disconnected, the next step is to mount the FASS pump assembly. Proper mounting ensures the pump operates efficiently and remains secure under the vibrations typical of a diesel truck.
Position Verification
Before mounting, place the pump assembly in the planned location. Verify that the port orientations align with the planned fuel line routing and that there is adequate clearance for all components. Mark the mounting hole locations to ensure accurate placement.
Surface Preparation
Clean the mounting surface thoroughly with brake cleaner to remove dirt, grease, rust, or undercoating. A clean surface ensures a solid electrical ground connection, which is essential for the pump's operation.
Secure Mounting
Using the provided bracket and hardware, bolt the pump assembly securely to the frame rail or another suitable location. Ensure the bracket and assembly are solid and free from excessive flex. Tighten all hardware to the manufacturer’s specifications.
Installation Procedures: Fuel Line Connections
Proper fuel line connections are crucial for the system’s performance and safety. Incorrect routing or installation can lead to leaks, reduced performance, or even pump damage.
Handling Tubing
Use a sharp tubing cutter for plastic or nylon lines to ensure clean, square cuts. Immediately deburr the inside and outside edges after cutting. Never use a regular utility knife for cutting fuel lines, as it can cause pinching and burrs that may lead to leaks.
Reservoir Tank to Pump Inlet (Supply Line)
Run the provided braided supply hose or push-lock hose from the reservoir tank outlet port to the inlet port on the FASS pump assembly. Ensure the hose length allows for gentle curves without stretching or kinking. Use high-quality hose clamps at each connection point. If the kit specifies double clamps, use them and tighten securely but avoid overtightening, which can crush the hose barb.
Secure the Discharge Line
Secure the discharge line every 12–18 inches along its path. Ensure the line is routed away from heat sources and sharp edges to prevent damage or wear over time.
Installation Procedures: Pump Return Line to Vehicle Return System
Correctly pluming the return line is essential for the pump to regulate pressure properly. Failure to install this line correctly can prevent the system from functioning as intended.
Locate the Vehicle's Fuel Return System
The vehicle’s fuel return system is typically located at the fuel pressure regulator cap on top of the secondary fuel filter housing. FASS kits provide specific fittings to adapt into this system. Common methods include:
- Replacing the factory filter cap with an FASS cap that has additional return ports.
- Using a tee fitting spliced into the factory return line near the filter head.
- Connecting directly to a dedicated return line fitting on the regulator cap.
Follow the kit instructions precisely for your vehicle model. Incorrect installation can lead to improper pressure regulation and potential pump failure.
Connect the Return Line
Connect the provided return line from the regulator port on the FASS pump to the connection point using appropriate fittings and hose. Ensure the connections are tight and the line is routed away from heat sources and abrasion points.
Installation Procedures: Electrical Wiring
Incorrect electrical installation is a leading cause of premature FASS pump failure. Proper wiring ensures the pump receives the correct power and is protected from electrical surges or short circuits.
Mount Relay and Fuse Holder
Secure the relay module and fuse holder assembly in a location within the engine compartment that is away from direct water spray, mud, and heat. Ensure the mounting is robust to resist vibration.
Connect Power Source
Connect the power source according to the kit instructions. Ensure all electrical connections are secure and insulated to prevent short circuits. Use appropriately rated fuses and relays to protect the pump and wiring.
Post-Installation Checks and Adjustments
After the installation is complete, several checks and adjustments should be made to ensure the system is operating correctly.
Observe Fuel Pressure
If a fuel pressure gauge is installed, verify that the pressure reading aligns with the pump’s specifications and the engine’s requirements. Initial adjustments may be necessary after the vehicle has been driven for a short period.
Pressure Adjustment
For FASS systems with an adjustable pressure regulator, avoid making significant adjustments until after the vehicle has been driven and the pressure has stabilized. Consult the specific kit instructions for pressure adjustment details.
Monitor Fluid Levels
Keep an eye on the reservoir tank level and the vehicle’s fuel gauge during the initial operation. This helps identify any potential leaks or issues with fuel flow.
Scan for Diagnostic Trouble Codes (DTCs)
Use an OBD-II scanner to check for any new diagnostic trouble codes that may have been triggered during installation. Clear any spurious codes and address any persistent codes that remain after the vehicle has been operated.
First Road Test
Once the system is installed and the initial checks are complete, take the vehicle on a short, gentle test drive. During this test, pay attention to the following:
- Engine performance: Ensure the engine runs smoothly with consistent power delivery and easy starting.
- Pump noise: Listen for any unusual or excessive vibration from the pump.
- Leaks: Re-inspect the entire system after the drive, especially when components are hot.
- Fuel pressure stability: If a pressure gauge is installed, confirm that the pressure remains stable during operation.
- Controller calibration and tuning: Follow FASS instructions for initial setup and tuning of adjustable systems, which often involve setting base pressures based on sensor readings.
Operational Guidance and Maintenance for Long-Term Reliability
To ensure the FASS fuel system continues to perform reliably over time, regular maintenance and operational best practices are essential.
Regular Inspection
Periodically inspect all fuel lines, fittings, and connections for signs of wear, leaks, or damage. Pay special attention to areas near heat sources or moving parts that could cause abrasion over time.
Fluid Management
Keep the reservoir tank filled with clean fuel and check the fuel filter regularly. Replace the filter according to the manufacturer’s recommended schedule to prevent contaminants from reaching the engine.
Extended Storage
If the vehicle is to be stored for an extended period, run the system periodically to lubricate the pump internals and prevent varnishing. Consult FASS for specific storage recommendations for your system.
Conclusion
A professional-grade FASS fuel pump installation is more than just attaching components—it is a precision process that requires careful planning, the right tools, and attention to detail at every step. By prioritizing safety, ensuring leak-proof plumbing, securing the pump properly, and following priming procedures, you can maximize the performance and longevity of your diesel engine.
The FASS system offers significant benefits, including improved fuel pressure stability, protection from contaminants, extended injector life, and enhanced overall engine performance. A well-installed FASS system can provide reliable service for hundreds of thousands of miles. Dedication during the installation phase ensures that the investment in the system delivers long-term value and performance.