The FASS Diesel Direct Replacement Pump (DDRP) is a high-performance fuel lift pump designed for 1998.5–2002 Dodge Ram 2500 and 3500 trucks equipped with Cummins 24V diesel engines. It serves as a cost-effective alternative to a full FASS fuel system, offering increased fuel flow, simplified installation, and improved reliability over the original factory lift pump. This guide is based on information from official manuals, technical descriptions, and user-reported installation details, with an emphasis on accuracy and adherence to the manufacturer’s specifications.
Overview of the FASS DDRP
The FASS DDRP is intended as a direct replacement for the factory lift pump in Dodge’s second-generation Cummins diesel engines. These trucks, known for their robust power and reliability, are also infamous for the weak factory fuel transfer pump, which can lead to frequent failures and costly repairs. The DDRP addresses these issues by providing a more durable and efficient pump solution.
According to the technical documentation, the DDRP increases fuel flow by 33% compared to the stock pump. It is designed to supply consistent fuel pressure to the VP44 injection pump, which is essential for both engine performance and cooling. The pump is mounted in the original factory location and uses the factory wiring harness, minimizing installation complexity. It is also backed by a warranty that can extend up to four years under certain conditions.
Installation Requirements and Kit Contents
The FASS DDRP comes with a comprehensive kit that includes all necessary components for installation. These components are designed to ensure compatibility with the factory fuel lines and to facilitate a straightforward installation process. The kit typically includes:
- The DDRP pump unit
- Rubber fuel line and fittings to replace the factory steel line
- Mounting hardware
- Installation manual
Additional components may be required depending on the truck’s existing setup. For example, users who have retrofitted an in-tank lift pump may also need a Fuel Sump Kit or a suction tube to ensure proper fuel delivery to the DDRP. The installation manual, which can be accessed via the manufacturer’s website, provides a detailed part list and step-by-step instructions.
Step-by-Step Installation Procedure
The installation process for the FASS DDRP is described as simple enough to be performed by a novice mechanic. The following steps are derived from the installation manual and user reports:
Preparation and Safety: Ensure the truck is turned off and the battery is disconnected to prevent electrical shorts during installation. Gather all necessary tools, including wrenches, pliers, and a screwdriver.
Removing the Factory Pump: Locate the factory lift pump in the original mounting position. Disconnect the fuel lines and electrical connections. Carefully remove the pump and set it aside.
Mounting the DDRP: Install the DDRP in the same location as the factory pump. Use the included mounting plate and hardware to secure the unit. Ensure that the mounting bolts are tightened to the manufacturer’s specifications.
Connecting Fuel Lines: Replace the factory steel fuel line with the rubber line provided in the DDRP kit. Attach the fittings securely and ensure there are no leaks. The factory wiring harness should be connected to the DDRP, which eliminates the need for additional electrical work.
Testing and Priming: After installation, it may be necessary to prime the pump. This can be done by placing the fuel line in a bucket of diesel and attempting to start the engine. If the pump does not start immediately, check for air in the fuel system and bleed it out as necessary.
Final Checks: Once the pump is running smoothly, perform a final inspection of all connections and ensure the pump is functioning as expected. Reconnect the battery and test the system under normal operating conditions.
Troubleshooting Common Issues
Despite the DDRP’s design for simplicity and reliability, some users have reported common issues that may arise during or after installation. These include:
Air in the Fuel System: Air in the fuel line can prevent the pump from starting. To resolve this, the user can perform the "5 Gallon Bucket Test," which involves placing the fuel line in a bucket of diesel and attempting to start the engine. If the pump still fails to start, the system may need to be bled of air manually.
Pump Noise or Cycling: If the pump sounds like it is turning on and off repeatedly, it may be due to a loose connection or an issue with the pump itself. Checking the motor and tightening the mounting bolts can often resolve this issue. In some cases, the pump may need to be returned for warranty service.
Electrical Issues: If the pump does not receive power or if the fuse blows, users should check for shorts in the wiring harness, damaged connections, or incorrect fuse ratings. It is also recommended to apply dielectric grease to the fuse contacts to prevent corrosion.
Compatibility and Configuration: The DDRP is not compatible with waste vegetable oil (WVO) or biodiesel fuels. Additionally, trucks with in-tank lift pumps may require additional components to ensure proper fuel delivery.
Optional Accessories and Enhancements
To maximize the performance and reliability of the DDRP, FASS offers several optional accessories. One such accessory is the DRP Relocation Kit, which allows the pump to be mounted closer to the fuel tank. This reduces the distance the pump must pull fuel from and ensures the fuel is delivered under pressure, which can improve pump efficiency and reduce motor strain.
Another optional component is the Fuel Sump Kit, which is recommended for trucks with retrofitted in-tank lift pumps. This kit ensures that the DDRP has a consistent supply of fuel and prevents issues related to fuel starvation.
Warranty and Support
The FASS DDRP comes with a warranty that initially lasts for one year but can be extended to four years if the user submits the required warranty information. This extension is an important consideration for users who want long-term reliability and support. In the event of a malfunction, users can contact FASS or an authorized service provider for assistance.
Conclusion
The FASS DDRP is a robust and reliable solution for 1998.5–2002 Dodge Cummins diesel truck owners looking to replace their factory lift pump. With increased fuel flow, a simplified installation process, and a strong warranty, it offers a compelling alternative to more complex fuel systems. By following the manufacturer’s installation instructions and addressing any potential issues with troubleshooting steps, users can ensure their truck’s fuel system operates at optimal efficiency.
For users who want further customization or enhanced performance, optional accessories such as the relocation kit or fuel sump kit can provide additional benefits. Overall, the DDRP represents a cost-effective and durable upgrade that can significantly improve the reliability and performance of the truck’s fuel system.