3900958
Expansion Plug
Cummins®

The Cummins 3900958 Expansion Plug is a component designed for use in commercial trucks. It serves a specific function within the vehicle’s systems, contributing to the overall maintenance and operational efficiency of the truck. Understanding its purpose and significance is important for fleet operators and maintenance personnel.

Basic Concepts of Expansion Plugs

Expansion plugs are mechanical devices used to seal openings in various systems, such as engines or cooling systems. They function by expanding upon installation to create a tight seal, preventing leaks and maintaining system integrity. These plugs find applications across automotive and industrial settings, where sealing solutions are required to ensure the proper functioning of equipment ¹.

Purpose of the 3900958 Expansion Plug

The Cummins 3900958 Expansion Plug plays a role in the operation of a truck by sealing specific openings within the engine or cooling system. Its function is to prevent coolant or other fluids from leaking out, thereby maintaining the system’s pressure and efficiency. This plug is integral to ensuring that the truck’s engine operates within optimal parameters ².

Key Features

The primary features of the Cummins 3900958 Expansion Plug include its material composition, which is designed to withstand the high temperatures and pressures within an engine environment. The plug’s design elements allow for easy installation and removal, while also ensuring a secure fit. Unique attributes such as corrosion resistance and durability enhance its performance, making it a reliable component for commercial truck applications ³.

Benefits

Using the Cummins 3900958 Expansion Plug offers several advantages. It contributes to improved system integrity by effectively sealing openings, which helps maintain the pressure and efficiency of the engine or cooling system. The plug’s enhanced durability ensures long-term performance, potentially leading to cost savings for fleet operators by reducing the need for frequent replacements or repairs ⁴.

Installation Process

Installing the Cummins 3900958 Expansion Plug requires following a step-by-step process to ensure a secure fit. The necessary tools include a hammer and a suitable installation tool. Best practices involve cleaning the installation site to remove any debris or old sealant, inserting the plug, and then using the installation tool to expand it into place. Ensuring the plug is properly seated is crucial for its effectiveness.

Troubleshooting Common Issues

Typical problems associated with expansion plugs include leaks or improper seating. Troubleshooting methods may involve checking the installation site for debris or damage, ensuring the plug is fully expanded, and verifying that it is the correct size for the opening. In some cases, replacing the plug may be necessary to resolve issues.

Maintenance Tips

Regular maintenance checks are recommended to ensure the longevity and effectiveness of the Cummins 3900958 Expansion Plug. This includes inspecting the plug for signs of wear or damage, ensuring it remains securely in place, and checking for any leaks in the system. Adhering to these maintenance procedures can help prevent issues and ensure the plug continues to perform its intended function.

Cummins Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a history spanning over a century, Cummins has established a strong reputation in the commercial truck industry for producing reliable and high-performance components. Their product range includes engines, powertrain components, and aftermarket parts, all designed to meet the demanding requirements of commercial vehicle operators.

Engines Compatible with 3900958

The Cummins Expansion Plug part number 3900958 is designed to fit a variety of Cummins engines, ensuring a secure and reliable seal. This part is essential for maintaining the integrity of the engine’s cooling system by preventing leaks and ensuring optimal performance.

15N Series

• 15N CM2380 M104B

4B3.9 Series

• 4B3.9

6B5.9 Series

• 6B5.9

6C8.3 Series

• 6C8.3

B4.5 Series

• B4.5
• B4.5 RGT

B5.6 Series

• B5.6 CM2670 B152B

B5.9 Series

• B5.9 CM2670 B166C
• B5.9 G
• B5.9 GAS PLUS CM556

B6.7 Series

• B6.7 CM2350 B135B
• B6.7 CM2670 B153B
• B6.7 CM2670 B164C
• B6.7 G CMOH6.0 B125

F3.8 Series

• F3.8 F102

ISB Series

• ISB (Chrysler)
• ISB CM2150
• ISB CM550
• ISB CM850
• ISB/ISD4.5 CM2150 B119
• ISB/ISD6.7 CM2150 SN
• ISB3.9 CM2220 B107
• ISB5.9 CM2880 B110
• ISB5.9 CM2880 B127
• ISB5.9 CM2880 B140

This part is engineered to fit seamlessly into the specified engines, providing a critical function in the engine’s overall operation.

Role of Part 3900958 Expansion Plug in Engine Systems

The 3900958 Expansion Plug is an essential component in various engine systems, ensuring optimal performance and reliability. Its primary function is to seal and pressurize specific areas within the engine block and related assemblies. Here’s how it integrates with different components:

Block and Short Block Assemblies

In the Block 6-B Short, Short 4BTA, Short E2 Incent, Short E3 Incent, Short Euro1, Short 6B Block, Short Block, Short Block Kit, Short E1 180 Block, Short E2 215/235 Block, Short E2 Block, and Short E215/235 Block, the expansion plug is used to seal cavities that are not in use. This prevents coolant or oil leakage, maintaining the integrity of the engine’s fluid systems.

Cylinder Block and Related Kits

For the Cylinder Block Kit and Cylinder Short Block, the expansion plug ensures that unused passages within the cylinder block are sealed. This is particularly important in multi-configuration engine blocks where certain passages may not be required for specific applications.

Crankshaft and Bearings

In the Crankshaft and Bearings assembly, the expansion plug may be used to seal off oil passages that are not utilized in a particular engine configuration. This helps in directing the oil flow efficiently to the necessary components, enhancing lubrication and reducing wear.

Engine Oil and Lubricating Systems

The Engine Oil Cooler and Lubricating Oil Cooler Module often incorporate expansion plugs to seal off sections of the cooler that are not in use. This ensures that the oil flow is directed correctly, optimizing cooling efficiency and maintaining oil temperature within specified parameters.

Exhaust Recirculation and Hand Hole Cover

In the Exhaust Recirculation system, the expansion plug can be used to seal off passages that are not part of the recirculation path, ensuring that the system operates efficiently. Similarly, in the Hand Hole Cover, expansion plugs may be employed to seal areas that are not intended for access or maintenance.

Lower Engine Gasket Kit and Side Oil Catch

The Lower Engine Gasket Kit often includes provisions for expansion plugs to seal off areas between the block and other components. In the Side Oil Catch system, expansion plugs help in directing the oil flow to the catch tank, preventing oil from entering unintended areas.

Long Block and Long Block Kit

In the Long Block and Long Block Kit, expansion plugs are used to seal various passages within the engine block that are not required for the specific engine configuration. This ensures that the long block operates efficiently without unnecessary fluid leakage.

By effectively sealing off unused passages and cavities, the 3900958 Expansion Plug plays a significant role in maintaining the efficiency and reliability of various engine systems.

Conclusion

The Cummins 3900958 Expansion Plug is a critical component in the maintenance and operation of commercial trucks. Its role in sealing and pressurizing specific areas within engine systems ensures optimal performance and reliability. Understanding its features, benefits, and proper installation and maintenance procedures is essential for fleet operators and maintenance personnel to ensure the longevity and effectiveness of this Cummins part.