3908001
Filler Cap
Cummins®

Introduction

The Cummins 3908001 Filler Cap is a critical component in the fueling systems of commercial trucks. It ensures the secure and efficient operation of the vehicle’s fuel system by maintaining the integrity of the fuel tank and preventing fuel spillage during refueling ¹.

Purpose of the 3908001 Filler Cap

The primary function of this Cummins part is to provide a secure closure for the fuel tank, preventing unauthorized access and fuel spillage. It is designed to fit snugly over the fuel tank opening, creating a seal that keeps contaminants out and fuel in. The cap also facilitates the refueling process by allowing a fuel nozzle to be inserted securely, minimizing spills and ensuring fuel is delivered directly into the tank ².

Key Features

The Cummins 3908001 Filler Cap is constructed from durable materials resistant to corrosion and wear, ensuring longevity and reliability. Its design includes a tamper-evident seal and a locking mechanism to deter unauthorized access. Additionally, the cap is designed to accommodate standard fuel nozzles, ensuring compatibility with common refueling equipment ³.

Benefits

Using the Cummins 3908001 Filler Cap offers several advantages. It enhances fuel security by providing a reliable seal and deterrent against tampering. The cap’s design also contributes to ease of use during refueling, reducing the likelihood of spills. Furthermore, its compatibility with Cummins fuel systems ensures seamless integration and optimal performance ⁴.

Installation Process

Installing the 3908001 Filler Cap involves several steps to ensure a secure fit. First, the fuel tank opening should be clean and free of debris. The cap is then aligned with the opening and turned clockwise until it locks into place. It is important to ensure that the cap is fully seated to achieve a proper seal.

Maintenance Tips

To maintain the performance of the 3908001 Filler Cap, regular inspection and cleaning are recommended. This includes checking for signs of wear or damage and ensuring that the sealing surfaces are free of dirt and debris. If the cap becomes difficult to turn or shows signs of leakage, it may need to be replaced.

Troubleshooting Common Issues

Common issues with the 3908001 Filler Cap may include difficulty in turning the cap or fuel leakage. If the cap is hard to turn, lubricating the threads with a suitable lubricant can help. In the case of fuel leakage, inspecting the cap for damage and ensuring it is properly seated can resolve the issue. If problems persist, replacement of the cap may be necessary.

Safety Considerations

When handling and maintaining the 3908001 Filler Cap, it is important to observe safety practices. This includes wearing appropriate personal protective equipment and ensuring that the area is well-ventilated when working around fuel. Proper storage of the cap, away from direct sunlight and extreme temperatures, is also recommended to maintain its integrity.

Environmental Impact

The use and disposal of the 3908001 Filler Cap should be considered in the context of environmental impact. Recycling options for the cap material should be explored, and proper waste management practices should be followed to minimize environmental harm.

Cummins Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a history of innovation and a commitment to quality, Cummins serves commercial truck markets with a range of products designed to enhance performance and reliability.

Compatibility with Cummins Engines

The Cummins part number 3908001, which is a Filler Cap, is compatible with a range of Cummins engines. This filler cap is designed to fit seamlessly with the following engine models:

• 4B3.9
• 6B5.9
• 6C8.3
• B5.9 G
• B5.9 GAS PLUS CM556
• C GAS PLUS CM556
• C8.3 G
• QSK19 CM500

These engines, while differing in specifications and applications, share a commonality in their design that allows the 3908001 filler cap to fit effectively. The cap is engineered to provide a secure seal, ensuring that the engine’s fuel or coolant system remains protected from contaminants and environmental elements.

Role of the 3908001 Filler Cap in Engine Systems

The 3908001 Filler Cap is an integral component in the operation and maintenance of various engine systems. Its primary function is to facilitate the addition of fluids, typically oil, into the engine while preventing contaminants from entering. This part interacts with several key components within the engine system, ensuring optimal performance and longevity.

Interaction with Flywheel and Housing

The 3908001 Filler Cap is often situated near the flywheel and housing. The flywheel, which is responsible for storing rotational energy, relies on proper lubrication to reduce friction and wear. The Filler Cap allows for the addition of oil, which then circulates to lubricate the flywheel and other moving parts. The housing, which encases various engine components, benefits from the Filler Cap by maintaining a sealed environment, preventing oil leaks and contamination.

Sensor Integration

Modern engines are equipped with sensors that monitor oil levels and conditions. The 3908001 Filler Cap often includes provisions for these sensors, allowing for real-time monitoring of oil levels. This integration ensures that the engine receives the appropriate amount of lubrication, enhancing efficiency and preventing damage from oil starvation or overfilling.

Oil Level Management

Accurate oil level management is essential for engine health. The 3908001 Filler Cap provides a convenient point for checking and adjusting oil levels. This is particularly important during maintenance checks, where precise oil levels are required to ensure proper lubrication of all engine components, including the support mounting structures that hold the engine in place.

Support Mounting Considerations

The support mounting system, which secures the engine to the vehicle’s frame, also benefits from the Filler Cap. Proper lubrication reduces the stress on these mounts by minimizing friction between moving parts. The Filler Cap ensures that the engine remains well-lubricated, thereby extending the lifespan of the support mounts and enhancing overall engine stability.

Conclusion

In summary, the Cummins 3908001 Filler Cap is a versatile and reliable component that fits a wide range of Cummins engines, ensuring that these engines remain protected and perform optimally. Its design and placement are tailored to facilitate easy maintenance while ensuring the engine operates within optimal parameters.