135675
Thermostat
Cummins®

The Cummins 135675 Thermostat is a component designed for use in commercial trucks, playing a significant role in the engine’s cooling system. Its primary function is to regulate the engine’s temperature, ensuring it operates within a specified range. This regulation is vital for maintaining engine efficiency, performance, and longevity. Thermostats, in general, are integral to engine management, as they help prevent overheating and underheating, both of which can lead to engine damage.

Basic Concepts of Thermostats

A thermostat is a device that senses the temperature of a system and performs actions to maintain the temperature within a set range. In the context of an engine cooling system, the thermostat monitors the engine’s temperature and controls the flow of coolant to the radiator. When the engine is cold, the thermostat remains closed, preventing coolant flow to the radiator and allowing the engine to warm up quickly. Once the engine reaches the optimal operating temperature, the thermostat opens, allowing coolant to circulate through the radiator, where it is cooled before returning to the engine. Maintaining optimal engine temperature is crucial for efficient combustion, reduced emissions, and prolonged engine life ¹.

Purpose of the Cummins 135675 Thermostat

The Cummins 135675 Thermostat is specifically engineered to regulate the engine temperature in commercial trucks. By controlling the flow of coolant, it ensures that the engine operates within its optimal temperature range. This regulation enhances engine performance and efficiency by facilitating proper combustion and reducing the risk of thermal stress on engine components. The thermostat’s role in temperature regulation is fundamental to the engine’s overall health and efficiency.

Key Features

The Cummins 135675 Thermostat is characterized by several key features that contribute to its functionality and durability. Its design incorporates high-quality materials that are resistant to corrosion and thermal stress, ensuring reliable performance under varying operating conditions. The thermostat is engineered to open and close at precise temperatures, providing accurate temperature regulation. Additionally, it features a robust construction that can withstand the rigors of commercial truck operation, offering longevity and consistent performance.

Benefits of Using the Cummins 135675 Thermostat

Utilizing the Cummins 135675 Thermostat offers several advantages for commercial truck operators. It contributes to improved engine efficiency by ensuring optimal operating temperatures, which can lead to fuel savings. Reduced wear and tear on engine components result from stable temperature regulation, enhancing the engine’s longevity. Furthermore, the thermostat’s reliable performance contributes to overall vehicle reliability, reducing the likelihood of unexpected breakdowns and maintenance costs. These benefits translate to cost savings and increased operational efficiency for fleet operators ².

Troubleshooting and Maintenance

Common issues with the Cummins 135675 Thermostat may include failure to open or close at the correct temperature, leading to overheating or underheating of the engine. Troubleshooting steps involve checking for proper installation, ensuring there are no obstructions in the coolant flow, and verifying that the thermostat is not stuck in one position. Regular maintenance practices, such as inspecting the thermostat during routine engine service and replacing it according to the manufacturer’s recommendations, can help ensure optimal performance and longevity. Signs of thermostat failure, such as inconsistent engine temperature or coolant leaks, should prompt further investigation and, if necessary, professional assistance.

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 reputation for quality, innovation, and reliability in the automotive and heavy-duty truck industries. The company’s commitment to excellence is evident in its extensive range of products, including the Cummins 135675 Thermostat, which embodies Cummins’ dedication to enhancing engine performance and efficiency through precision engineering and durable design.

Thermostat Compatibility with Cummins Engines

The thermostat part number 135675, manufactured by Cummins, is designed to fit a variety of Cummins engines. This part is integral in maintaining the optimal operating temperature of the engine by regulating the flow of coolant. Here is a detailed look at the compatibility of this thermostat with various Cummins engines:

Medium-Duty Engines

• 6B5.9: This engine benefits from the thermostat’s precise temperature control, ensuring efficient engine performance.
• K19: The thermostat’s compatibility with the K19 engine helps maintain consistent engine temperatures, enhancing reliability.
• K38: The 135675 thermostat is engineered to work seamlessly with the K38 engine, providing reliable thermal regulation.
• K50: This engine is another beneficiary of the thermostat’s design, ensuring smooth operation and longevity.

Industrial and Marine Engines

• KTA38GC CM558: The thermostat is suitable for this industrial engine, offering precise temperature management for heavy-duty applications.
• N14 G: The 135675 thermostat is compatible with the N14 G engine, ensuring efficient thermal regulation in demanding environments.
• N14 MECHANICAL: This variant of the N14 engine also benefits from the thermostat’s precise control, maintaining optimal operating temperatures.
• QSK50 CM2150 MCRS: The thermostat ensures that this marine engine operates within its ideal temperature range, enhancing performance and durability.
• QSK50 CM2350 K108: The 135675 thermostat is designed to fit this engine, providing reliable temperature regulation for marine applications.
• QSK60 G CM2358 K110: This engine is another marine application that benefits from the thermostat’s precise thermal management.
• QSK60G: The thermostat’s compatibility with this engine ensures consistent performance in marine environments.
• QSNT14 CM876 N102: The 135675 thermostat is engineered to fit this engine, offering reliable temperature control for industrial and marine applications.

The thermostat part number 135675 is a versatile component that ensures efficient thermal regulation across a wide range of Cummins engines, from medium-duty to industrial and marine applications. Its design allows it to maintain optimal engine temperatures, enhancing performance and longevity.

Role of Part 135675 Thermostat in Engine Systems

The part 135675 thermostat is an integral component in the thermal management of engine systems. It operates in conjunction with several other components to ensure optimal engine performance and longevity.

Interaction with Water Outlet and Connections

The thermostat is positioned between the engine and the water outlet. Its primary function is to regulate the flow of coolant through the engine. When the engine is cold, the thermostat remains closed, directing coolant flow back into the engine to warm it up quickly. As the engine temperature rises, the thermostat gradually opens, allowing coolant to flow through the water outlet and into the radiator for cooling. This process is essential for maintaining the engine within its optimal operating temperature range.

Integration with Thermostat Housing and Support Assembly

The thermostat is typically housed within a thermostat housing, which may include a support assembly. This housing protects the thermostat and provides a secure mounting point within the engine system. The housing also facilitates easy access for maintenance and replacement of the thermostat.

Role in Cooling System Components

In systems that include a cooler or a torque converter oil cooler, the thermostat helps maintain the efficiency of these components by ensuring that the coolant reaches the appropriate temperature before circulating through them. This is particularly important in high-performance or heavy-duty engines where maintaining precise temperatures can significantly impact overall efficiency and reliability.

Connection to Engine Control Systems

Modern engines often incorporate engine control units (ECUs) that monitor and adjust various parameters, including coolant temperature. The thermostat works in tandem with these control systems, providing feedback on engine temperature to allow the ECU to make necessary adjustments to fuel delivery, ignition timing, and other critical functions.

Use in Overhaul and Spare Parts Kits

Part 135675 is commonly included in engine overhaul kits and spare parts kits. These kits are designed to provide all necessary components for a comprehensive engine rebuild or repair. The thermostat is a key component in these kits, ensuring that the rebuilt engine will maintain proper thermal regulation from the outset.

Manifold and Housing Assemblies

In engines with water manifolds, the thermostat plays a role in directing coolant flow through these manifolds to various parts of the engine, including the exhaust manifold. Proper thermostat function ensures that all engine components receive adequate cooling, preventing hotspots and potential damage.

On-Board Spares and PDC Kits

For applications requiring on-board spares or PDC (Pre-Delivery Condition) kits, the inclusion of part 135675 ensures that a replacement thermostat is readily available should the primary unit fail. This is particularly important in remote or high-stress operating environments where immediate replacement can prevent engine downtime.

Conversion Kits and Depot Parts

In scenarios where engine systems are being upgraded or converted, the thermostat may be part of a conversion kit. These kits often include base and depot parts to facilitate the transition to a new cooling system configuration, ensuring compatibility and continued efficient operation.

Conclusion

The Cummins 135675 Thermostat is a vital component that interacts with various engine systems to maintain optimal operating temperatures, ensure efficient cooling, and support overall engine performance and reliability. Its design and functionality are crucial for the efficient operation of commercial trucks, contributing to fuel savings, reduced maintenance costs, and prolonged engine life.