Cummins NT855 Engine Parts – Gasket Kit Section

The Cummins NT855 engine, a proven member of the Cummins 855 Series, relies on a wide range of precision gaskets and seals to maintain reliable performance under heavy duty conditions. Gaskets prevent leaks, ensure proper compression, and protect components from contamination. At Diesel Pro Power, we supply a complete selection of Cummins NT855 gasket kits and individual gaskets, trusted by more than 40,000 satisfied customers worldwide for both marine and industrial diesel applications.

Whether you are performing a full engine overhaul, replacing a cylinder head, or addressing a minor coolant or oil leak, our NT855 gasket catalog provides everything you need in one place.

Complete Gasket Sets for Cummins NT855

Upper Gasket Set for Cummins NT855

The upper gasket set includes all critical sealing components for the top half of the engine. It typically contains head gaskets, intake and exhaust gaskets, rocker cover gaskets, injector seals, and other related components. This set is ideal when servicing cylinder heads, valves, or upper-end components of the NT855.

Lower Gasket Set for Cummins NT855

The lower gasket set covers the engine block and lower-end components. It usually includes oil pan gaskets, crankshaft seals, water pump gaskets, fuel pump gaskets, and related seals. This set is essential when rebuilding or maintaining the crankshaft, pistons, oil system, and water pump areas of the NT855.

Individual Gaskets and Seals for Cummins NT855

Exhaust Manifold Gasket

The exhaust manifold gasket provides a tight seal between the cylinder head and exhaust manifold, preventing harmful gases from leaking. On the NT855, six are required per engine. Using a high-quality manifold gasket helps maintain proper exhaust flow and prevents overheating or exhaust leaks that can reduce engine efficiency.

Oil Pan Gasket

The oil pan gasket seals the connection between the engine block and oil pan, keeping the lubrication system leak-free. A damaged oil pan gasket can lead to oil loss, reduced lubrication, and costly repairs. Replacing the gasket with a reliable seal is a critical step in NT855 engine maintenance.

Valve Cover Gaskets (New and Old Styles)

Cummins NT855 engines may use either the new style valve cover gasket (durable, modern materials) or the older cork-style valve cover gasket. Both options ensure proper sealing of the valve cover, preventing oil leaks around the rocker area. When servicing the top end of the NT855, always inspect and replace valve cover gaskets to maintain performance.

Fuel Pump Gasket

This gasket provides a seal for the fuel pump coupling, ensuring that the fuel system remains tight and leak-free. Since fuel delivery is critical to the NT855’s combustion process, maintaining this gasket in top condition is essential for performance and efficiency.

Fan Hub Oil Seal

The oil seal for the NT855 fan hub prevents lubrication leaks at the fan drive connection. A failed oil seal can result in oil loss and premature bearing wear. Replacing it as part of routine maintenance prevents overheating and extends the life of the cooling system.

Cooling System Gaskets for NT855

Coolant Pump Gaskets

The Cummins NT855 coolant pump uses multiple gaskets to maintain a proper seal. These include the water inlet connection gasket, the mounting gasket, and the outlet connection O-ring seal. Together, they ensure that coolant flows efficiently without leakage. Replacing these gaskets during water pump service prevents overheating and ensures stable operating temperatures.

Sealants, Compounds, and Gasket Makers

In addition to physical gaskets, Cummins NT855 engines often require sealants and jointing compounds for areas exposed to high heat, pressure, or vibration. Diesel Pro Power carries a wide range of gasket makers and compounds suitable for NT855 and other Cummins engines.

High-Temperature Jointing Compound

This compound is designed for exhaust and turbocharger connections, withstanding extreme temperatures (up to 760°C). It is ideal for applications where metal surfaces expand under heat and require a flexible, high-strength seal.

Gasket Spray Sealant

High-tack gasket spray helps hold cut gaskets in place during assembly and provides an additional sealing layer. It is widely used on NT855 engines during overhauls to ensure leak-free performance.

Liquid Gasket Maker (3H)

The liquid gasket maker is useful for sealing irregular surfaces or replacing traditional gaskets in certain low-pressure applications. It provides flexibility and durability, ensuring reliable sealing in NT855 service environments.

Silicone RTV Gasket Makers

Available in multiple formulas—standard, high-temperature, and sensor-safe—the silicone gasket makers are designed for sealing flanges, water connections, and other areas exposed to vibration. The sensor-safe versions are compatible with electronic engine sensors, preventing interference or damage.

Non-Hardening Pliable Sealant

This flexible sealant never hardens, making it useful for components that may require future disassembly. It provides an oil- and fuel-resistant seal that is ideal for NT855 engines in marine environments.

Threadlocker Compounds

High-strength red threadlocker secures bolts in high-vibration areas such as manifolds, pumps, and accessory mounts. By preventing loosening, it ensures long-term reliability of NT855 assemblies.

Cold Weld Compound (J-B Weld)

For emergency repairs or reinforcement of metal surfaces, J-B Weld provides a durable bonding solution. While not a replacement for gaskets, it is an essential addition to any NT855 maintenance toolkit.

Why Use Genuine NT855 Gaskets and Seals?

The Cummins NT855 is a heavy-duty engine built for industrial, marine, and power generation applications. Operating under high compression and extreme temperatures, it demands precision-engineered gaskets and seals. Using non-genuine or low-quality replacements can result in:

• Oil and coolant leaks

• Loss of compression and performance

• Increased operating temperatures

• Premature wear of internal components

• Expensive downtime and repairs

Diesel Pro Power supplies only reliable, proven gaskets and gasket kits designed for the NT855 and related Cummins engines.

Trusted by 40,000+ Customers Worldwide

With more than four decades of experience, Diesel Pro Power is the leading source for Cummins NT855 gaskets, gasket sets, and sealants. Customers around the globe trust us for fast shipping, knowledgeable support, and reliable parts that keep engines running at peak efficiency.