3937759
Filler Cap
Cummins®

Introduction

The Cummins 3937759 Filler Cap is a component designed for use in commercial trucks. Its primary role is within the vehicle’s fuel system, where it facilitates the addition of fuel to the tank while ensuring that spills and contamination are minimized. This part is integral to maintaining the efficiency and safety of the truck’s fuel system.

Purpose and Function

The filler cap serves a vital function in the truck’s fuel system by providing a secure point for refueling. It is engineered to allow fuel to be added to the tank efficiently while preventing spills that could pose safety hazards or lead to fuel wastage. Additionally, the cap acts as a barrier against contaminants such as dirt and water, which could compromise the quality of the fuel and affect engine performance. The design of the cap includes a sealing mechanism that ensures a tight fit on the fuel tank, maintaining the integrity of the fuel system ¹.

Key Features

The Cummins 3937759 Filler Cap is characterized by several key features that enhance its performance and durability. It is constructed from high-quality materials that are resistant to corrosion and wear, ensuring longevity even in demanding commercial environments. The cap’s design incorporates a robust sealing mechanism that provides a secure fit on the fuel tank, preventing leaks. Additionally, the cap is easy to operate, featuring a user-friendly design that allows for quick and effortless refueling.

Benefits

The use of the Cummins 3937759 Filler Cap offers several benefits. It contributes to the overall integrity of the fuel system by preventing leaks and contamination, which can lead to engine damage and reduced performance. The cap’s design ensures ease of use during refueling, minimizing the risk of spills and making the process more efficient. Furthermore, its durable construction and reliable performance contribute to the long-term reliability of the truck’s fuel system.

Installation and Usage

Proper installation and usage of the Cummins 3937759 Filler Cap are crucial for ensuring optimal performance and longevity. The cap should be installed according to the manufacturer’s guidelines to ensure a secure fit on the fuel tank. Users should follow recommended procedures for refueling, ensuring that the cap is properly sealed after use to maintain the integrity of the fuel system.

Maintenance and Troubleshooting

Regular maintenance of the Cummins 3937759 Filler Cap is important for ensuring its continued performance and durability. This includes periodic inspection for signs of wear or damage, such as cracks or corrosion, which could compromise the cap’s sealing ability. Common issues that may arise include leaks or difficulty in opening the cap, which can often be addressed through proper maintenance and care. In the event of a leak, it is important to inspect the cap and fuel tank for damage and replace any compromised components as necessary ².

Safety Considerations

When handling and maintaining the Cummins 3937759 Filler Cap, it is important to observe proper safety precautions. This includes avoiding fuel spills by ensuring the cap is securely sealed after refueling. Additionally, users should be cautious of static electricity when refueling, as it can pose a fire hazard. Proper handling techniques and the use of appropriate personal protective equipment can help mitigate these risks.

Environmental Impact

The Cummins 3937759 Filler Cap plays a role in minimizing the environmental impact of commercial truck operations. By preventing fuel spills and ensuring the integrity of the fuel system, it helps reduce the risk of fuel contamination and associated environmental hazards. Additionally, the cap’s design contributes to the efficient use of fuel, which can lead to reduced emissions and a lower environmental footprint.

Cummins Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes a wide range of power solutions, including engines, filtration, and emissions control technologies. With a history of innovation and a commitment to quality, Cummins serves commercial truck customers around the world, providing reliable and efficient power solutions that meet the demands of modern transportation.

Cummins Engine Filler Cap Compatibility

The Cummins part 3937759, a Filler Cap, is designed to fit a variety of Cummins engines. This part is integral for maintaining the integrity of the engine’s fuel system by preventing contaminants from entering and ensuring proper fuel vapor management. Below is a detailed breakdown of the engines compatible with this filler cap:

ISB Series

• ISB CM550
• ISB CM850
• QSB5.9 44 CM550
• QSB5.9 CM850

These engines, part of the ISB and QSB5.9 series, are commonly used in medium-duty and heavy-duty applications. The filler cap ensures that the fuel system remains sealed and protected against external elements.

ISC Series

• ISC CM2150
• ISC CM554
• ISC CM850
• QSC8.3 CM554
• QSC8.3 CM850 (CM2850)

The ISC series engines, including those with the QSC8.3 designation, are typically found in heavy-duty applications. The filler cap is crucial for maintaining the fuel system’s efficiency and reliability in these demanding environments.

ISL Series

• ISL CM2150
• ISL CM554
• ISL9 CM2150 SN
• ISL9.5 CM2880 L138

These ISL engines are known for their high power output and efficiency. The filler cap ensures that the fuel system remains sealed, preventing contamination and ensuring optimal performance.

L Series

• L8.9
• L8.9 CM2670 L134C
• L8.9 L121
• QSL8.9 CM2150 L141
• QSL9 CM554
• QSL9 CM850 (CM2850)

The L series engines, including the QSL variants, are widely used in various applications. The filler cap is essential for maintaining the fuel system’s integrity, ensuring that the engine operates smoothly and efficiently.

QSB6.7 Series

• QSB6.7 CM850 (CM2850)
• QSB6.7 M CM2250

These engines are known for their robust performance and reliability. The filler cap ensures that the fuel system remains sealed, protecting it from contaminants and ensuring optimal engine performance.

QSC8.3 Series

• QSC8.3 CM2880 C102

The QSC8.3 series engine is designed for heavy-duty applications. The filler cap is essential for maintaining the fuel system’s integrity, ensuring that the engine operates efficiently and reliably.

This filler cap is a critical component for all these engines, ensuring that the fuel system remains sealed and protected against contaminants. It is essential for maintaining the engine’s performance and longevity.

Role of Part 3937759 Filler Cap in Engine Systems

The part 3937759 Filler Cap is an integral component in the operation of several key engine systems. Its primary function is to seal the oil fill arrangement, ensuring that the engine’s lubrication system remains intact and functions efficiently.

Oil Fill Arrangement

In the oil fill arrangement, the Filler Cap plays a significant role by providing a secure closure for the oil tank. This prevents contaminants such as dirt and moisture from entering the oil, which could otherwise lead to engine wear and reduced performance. The cap also maintains the proper pressure within the oil system, which is essential for the efficient circulation of oil throughout the engine.

Valve Cover

The Filler Cap is often located on the valve cover, which houses the engine’s valve train components. By sealing the valve cover, the Filler Cap helps to keep the interior of the cover clean and free from debris. This is important for the proper functioning of the valves, as any contamination could interfere with their operation and lead to decreased engine efficiency.

Valves

Indirectly, the Filler Cap contributes to the health of the engine’s valves. By ensuring that the oil system is sealed and pressurized correctly, the Filler Cap helps to deliver clean, pressurized oil to the valve train. This lubrication is vital for the smooth operation of the valves, reducing friction and wear, and ensuring that the valves open and close at the correct times.

Valve Cover Gasket

The Filler Cap works in conjunction with the valve cover gasket to create a tight seal. The gasket fills any gaps between the valve cover and the engine block, and the Filler Cap presses down on the gasket to ensure a complete seal. This is important for preventing oil leaks, which could lead to a loss of lubrication and potential engine damage.

Conclusion

In summary, the Cummins 3937759 Filler Cap is a key component in maintaining the integrity of the engine’s oil system and protecting critical engine components such as the valve cover and valves. Its role in sealing the oil fill arrangement and valve cover is essential for the overall performance and longevity of the engine.