3939570
Captive Washer Cap Screw
Cummins®

Introduction

The Captive Washer Cap Screw 3939570 is a specialized fastener produced by Cummins, a leading manufacturer in the commercial truck industry. This screw is designed for use in various applications within commercial trucks, ensuring secure fastening of components that are vital for the vehicle’s operation and maintenance.

Basic Concepts

A Captive Washer Cap Screw, such as the 3939570, consists of a screw with an integrated washer that is captive, meaning it is permanently attached to the screw. This design ensures that the washer remains in place during installation, reducing the risk of loss and simplifying the fastening process. The screw functions by threading into a pre-drilled hole, where it compresses the washer against the surface, creating a secure and stable connection ¹.

Role in Truck Operation

The 3939570 Captive Washer Cap Screw plays a significant role in the operation and maintenance of commercial trucks. It is used to secure various components, such as engine parts, body panels, and chassis elements. By providing a reliable fastening solution, this screw helps maintain the structural integrity and functionality of the truck, ensuring that components remain securely in place under various operating conditions ².

Key Features

The 3939570 Captive Washer Cap Screw is characterized by several key features that enhance its performance. Its design includes a captive washer that is integrated into the screw, ensuring that the washer does not become misplaced during installation. The screw is made from high-quality materials, offering durability and resistance to corrosion. Additionally, the screw features a hexagonal head, allowing for easy installation and removal using common tools ³.

Benefits

The use of the 3939570 Captive Washer Cap Screw offers several benefits. Its design simplifies the installation process by eliminating the need to handle a separate washer, reducing the risk of washer loss and ensuring consistent fastening quality. The screw’s high-quality material and design contribute to improved reliability, making it suitable for use in demanding commercial truck applications. Furthermore, the ease of installation and maintenance of this screw can lead to cost savings and increased efficiency in truck maintenance operations ⁴.

Troubleshooting and Maintenance

Common issues with the 3939570 Captive Washer Cap Screw may include corrosion, stripping of the screw head, or loosening over time. To address these issues, regular inspection and maintenance are recommended. Ensuring that the screw and surrounding areas are clean and free from debris can prevent corrosion. Using the appropriate tools and techniques during installation can help avoid stripping the screw head. If loosening is detected, re-tightening the screw or replacing it may be necessary to maintain secure fastening.

Cummins Captive Washer Cap Screw 3939570 Compatibility with Engine Models

The Cummins Captive Washer Cap Screw part number 3939570 is designed to fit seamlessly with a variety of Cummins engine models. This part is integral in securing components within the engine assembly, ensuring stability and reliability. Below is a detailed breakdown of the engine models that are compatible with this specific part:

4B3.9, 6B5.9, 6C8.3, B4.5, B5.9 CM2670 B166C

The 4B3.9, 6B5.9, 6C8.3, B4.5, and B5.9 CM2670 B166C engines are mid-range power units often utilized in various industrial and commercial applications. The Captive Washer Cap Screw 3939570 is used in these engines to secure critical components, ensuring that the engine operates smoothly and efficiently.

F4.5 CM2620 F141C, L8.9, L8.9 L121

The F4.5 CM2620 F141C, L8.9, and L8.9 L121 engines are part of Cummins’ lineup of high-performance engines. These engines are known for their robust construction and are often used in heavy-duty applications. The Captive Washer Cap Screw 3939570 plays a crucial role in maintaining the integrity of these engines by securing various parts under high stress and load conditions.

L9.3 L105, L9.5 L117

The L9.3 L105 and L9.5 L117 engines are designed for applications requiring a balance of power and efficiency. The Captive Washer Cap Screw 3939570 is used in these engines to ensure that all components are tightly secured, contributing to the overall reliability and longevity of the engine.

QSB3.9 30 CM550, QSB5.9 30 CM550, QSC8.3 CM850 (CM2850)

The QSB3.9 30 CM550, QSB5.9 30 CM550, and QSC8.3 CM850 (CM2850) engines are part of Cummins’ Quantum Series, known for their advanced technology and performance. These engines are used in a variety of applications, from agricultural to construction. The Captive Washer Cap Screw 3939570 is essential in these engines for securing components that are subject to high rotational speeds and varying loads.

By ensuring that the Captive Washer Cap Screw 3939570 is used in these engines, Cummins maintains the high standards of quality and performance that their customers expect. This part is a testament to Cummins’ commitment to providing reliable and durable components for their engines.

Role of Part 3939570 Captive Washer Cap Screw in Engine Systems

The 3939570 Captive Washer Cap Screw is integral to the secure assembly and operation of various engine components. It ensures that parts remain firmly in place, which is essential for the efficient functioning of the engine system.

Fuel System Integration

In the fuel system, the 3939570 Captive Washer Cap Screw is used to secure components such as the fuel filter, fuel filter assembly kit, and fuel filter kit. It plays a significant role in maintaining the integrity of the fuel filter plumbing, ensuring there are no leaks and that the fuel flow is consistent. Additionally, it is employed in the Bosch fuel pump kit to secure the fuel pump and its coupling, contributing to the reliable operation of the fuel pump.

Air Intake and Heater Systems

For the air intake heater and air heater starting systems, the 3939570 Captive Washer Cap Screw is utilized to fasten the banjo connector screw and other critical components. This ensures that the air intake system remains sealed and operates efficiently, which is vital for cold-start performance and overall engine efficiency.

Electronic Control Module and Wiring

In the electronic control module wiring harness, the 3939570 Captive Washer Cap Screw is used to secure various connections and components. This ensures that the wiring remains intact and that electrical connections are secure, which is essential for the proper functioning of the engine’s electronic systems.

Fuel Transfer and Plumbing

The screw is also crucial in the fuel transfer pump and its plumbing. It secures the fuel transfer pump to its mounting points and ensures that the fuel lines are properly attached, preventing any fuel leaks and ensuring a smooth fuel transfer process.

Accessories and Conversion Kits

In accessories and conversion kits, such as the VE conversion kit and fuel pump conversion kits, the 3939570 Captive Washer Cap Screw is used to secure various components. This includes the fuel shutoff valve kit and other accessories, ensuring that these parts are firmly in place and function as intended.

Overall, the 3939570 Captive Washer Cap Screw is a versatile fastener that plays a significant role in the secure assembly and reliable operation of numerous engine components across different systems.

Conclusion

The 3939570 Captive Washer Cap Screw by Cummins is a critical component in the secure assembly and reliable operation of various engine systems. Its design, featuring an integrated captive washer, simplifies installation and ensures consistent fastening quality. The screw’s high-quality materials and hexagonal head design contribute to its durability, resistance to corrosion, and ease of use. By securing critical components in engines, this part plays a vital role in maintaining the structural integrity and functionality of commercial trucks. Regular maintenance and proper use of the screw can lead to cost savings and increased efficiency in truck maintenance operations.