KM 12V Billet Valve Cover O-ring and Seal Kit (KM-Seal-Kit-5.9L-02) for 1989-2002 Cummins 5.9L

Cummins 5.9L Seal Kit for 12-Valve Valve Covers and Engine Service

The KM 12V Billet Valve Cover O-Ring and Seal Kit is a practical service solution for 1989–2002 Cummins 5.9L engines. This kit combines two commonly used sealing components into one convenient package, making it ideal for maintenance, repairs, and performance work on 12-valve Cummins platforms.

Instead of sourcing individual seals, this kit provides the hardware most often replaced during valve cover installs, fuel system service, and oil system work.

Reliable Sealing for Fuel and Oil Applications

This Cummins 5.9L seal kit includes M8 copper crush washers, which seal banjo fittings and fluid connections under high pressure. These washers deform correctly during installation, creating a tight seal even in high-vibration and high-temperature environments.

Because copper resists heat and corrosion, these washers work well for fuel lines, oil feeds, and return connections. As a result, they help prevent seepage that often occurs with reused or hardened washers.

Durable –158 O-Rings for Rebuilds and Upgrades

In addition, the kit includes –158 O-rings made from oil-resistant material designed for long-term exposure to heat and petroleum products. These O-rings commonly seal ports, plugs, housings, and billet components across the Cummins 5.9L engine.

Whether used on billet valve covers, fuel system components, or accessory housings, these O-rings maintain elasticity and sealing pressure over time. This helps reduce leaks during both daily driving and high-performance use.

Ideal for Shops, Builders, and Preventive Maintenance

Because these seals are used across multiple Cummins systems, this kit works well for routine service, engine rebuilds, and performance upgrades. It also serves as a smart restock item for shops that frequently work on 12-valve Cummins engines.

Instead of reusing worn seals, installing fresh O-rings and washers ensures proper sealing and reduces the chance of future leaks.

Built for Cummins 5.9L Reliability

If you service or build Cummins 12-valve engines, this seal kit provides a simple, reliable solution for common sealing needs. It saves time, improves consistency, and supports clean, professional results on every install.