Cummins ISB 5.9 Parts - Oil Section

Cummins ISB 5.9L Oil Pump & Lubrication System Components

The lubrication system in your Cummins ISB 5.9L is the lifeline of the engine. It ensures that all moving parts—from the crankshaft to the turbocharger bearings—receive a continuous supply of clean, pressurized oil. A properly functioning oil pump is critical to maintaining oil pressure, preventing friction wear, and extending engine life. At Diesel Pro Power, we provide high-quality OEM-spec oil pumps and supporting components, designed to deliver reliable performance for marine and industrial Cummins ISB 5.9L engines. With over 40,000 satisfied customers worldwide, we supply trusted solutions for both preventative maintenance and complete engine overhauls.

Role of the Oil Pump in the Cummins ISB 5.9L Engine

The oil pump is responsible for drawing oil from the oil pan, pressurizing it, and distributing it through the lubrication passages of the engine. It not only lubricates components but also helps in cooling them and removing microscopic debris. In the Cummins ISB 5.9L, oil pumps can vary depending on the engine’s configuration—specifically whether it has a front gear train or rear gear train setup. These configurations also determine the type of gear teeth (helical or straight) used in the oil pump pinions, which affects how the pump meshes with the camshaft or crankshaft drive gears.

Oil Pumps for Cummins ISB 5.9L Engines

Rear Gear Train Oil Pumps – Helical Gear Design

For certain ISB 5.9L engines, the oil pump is located at the rear of the block and uses 23/24 helical teeth pinions. Helical gears are known for smooth operation and quieter performance due to the angled tooth design. These pumps are engineered to maintain consistent oil pressure under various load conditions, making them ideal for high-hour marine and industrial duty cycles.

Front Gear Train Oil Pumps – Helical Gear Design

Some ISB 5.9L models feature a front-mounted oil pump with 23/24 helical teeth. Front gear train pumps are preferred in certain applications for easier access during maintenance. Like their rear-mounted counterparts, they deliver steady lubrication and are built for long-term durability in demanding environments.

Rear Gear Train Oil Pumps – Straight Gear Design

In other ISB 5.9L configurations, the oil pump uses 22/24 straight teeth pinions. Straight gears offer high strength and straightforward meshing but can produce slightly more noise compared to helical gears. These pumps are rugged and dependable, designed to withstand the torque demands of industrial and commercial-grade ISB engines.

Front Gear Train Oil Pumps – Straight Gear Design

This variant also uses 22/24 straight teeth but is mounted at the front of the engine. Its design allows for efficient power transfer from the gear train while maintaining the oil flow rates required for proper engine lubrication.

Supporting Lubrication System Components

An effective lubrication system requires more than just the oil pump. Diesel Pro Power offers a full range of supporting parts for the Cummins ISB 5.9L, ensuring complete oil system reliability.

Oil Coolers

Oil coolers are essential for regulating oil temperature, preventing overheating, and preserving oil viscosity. Options include:

• 5-plate oil coolers – Compact yet effective for moderate-duty applications.

• 7-plate oil coolers – Increased cooling capacity for heavy-duty or high-temperature environments.

• Rear gear train-specific oil coolers – Designed to fit specific ISB layouts for optimal installation and cooling performance.

Oil Pan Gaskets

A durable oil pan gasket prevents leaks at the oil sump, ensuring the lubrication system maintains its capacity. Made from high-quality materials, these gaskets resist heat and oil degradation.

Oil Pick-Up Tube Gaskets

The gasket for the oil pick-up tube seals the connection between the tube and the oil pump, preventing air intrusion that could cause cavitation or loss of oil pressure.

Oil Cooler Cover Gaskets

These gaskets ensure a tight seal between the oil cooler housing and its cover, preventing leaks and maintaining system efficiency.

Oil Cooler Core Gaskets

These gaskets provide a secure seal for the oil cooler core itself, ensuring that coolant and oil passages remain separate and preventing cross-contamination.

Oil Filtration & Related Components

A clean oil supply is just as critical as adequate oil pressure. Cummins ISB 5.9L engines use high-capacity spin-on oil filters designed to capture contaminants without restricting flow.

Spin-On Oil Filters

• Standard height filters – Suitable for most applications, balancing filtration capacity with compact size.

• Extended height filters – Increased filtration surface area for longer service intervals and heavy-duty environments.

Oil Filter Removal Tools

To simplify maintenance, we offer adjustable oil filter wrenches compatible with Cummins ISB 5.9L spin-on filters, as well as those used on Detroit Diesel and Caterpillar engines.

Oil Pressure Monitoring

Maintaining the correct oil pressure is critical for engine protection. We provide a range of oil pressure switches and gauges for Cummins ISB 5.9L engines.

Oil Pressure Switches

Available in multiple set points:

• 5 PSI make/break

• 10 PSI make/break

• 20 PSI make/break

• 27 PSI make/break
  These switches are essential for activating warning systems or shutting down the engine to prevent damage during low-oil-pressure events.

Mechanical & Electrical Gauges

• Mechanical gauges – Directly measure oil pressure without electrical components.

• Electrical gauges (12V & 24V) – Provide dashboard readouts and can integrate with alarm systems.

Maintenance Recommendations for the Cummins ISB 5.9L Oil System

• Inspect oil pump gears during major services or if low oil pressure symptoms occur.

• Replace gaskets and seals during any oil system component change to prevent leaks.

• Monitor oil pressure using a reliable gauge; pressure outside the manufacturer’s specifications should be addressed immediately.

• Change oil filters at recommended intervals, or more often in severe-duty environments.

• Use OEM-quality components to maintain the integrity of the lubrication system and prevent premature engine wear.

Why Choose Diesel Pro Power for Cummins ISB 5.9L Oil Pumps & Components?

• Global shipping with fast delivery times.

• Proven reliability – Trusted by over 40,000 customers.

• OEM-spec parts – Ensuring proper fit and long-term durability.

• Expert support – Our team can help identify the correct oil pump configuration for your specific ISB engine CPL and gear train layout.