Cummins NH855 Engine Parts – Gasket Section

The Cummins NH855 engine relies on a comprehensive set of gaskets and seals to ensure leak-free operation across the cylinder head, exhaust system, oil pan, coolant system, and accessory components. Gaskets are critical to maintaining engine performance by sealing combustion pressures, preventing coolant and oil leaks, and reducing wear on surrounding components.

Diesel Pro Power supplies high-quality gaskets and gasket sets for the Cummins NH855 engine, trusted by more than 40,000 satisfied customers worldwide. Whether you are performing a top-end rebuild, a complete overhaul, or simply replacing a worn seal, our gasket catalog covers every critical component.

Exhaust Manifold Gaskets for Cummins NH855

Exhaust manifold gaskets are essential for maintaining a tight seal between the exhaust manifold and cylinder head. On the NH855 engine, six exhaust manifold gaskets are required per engine, ensuring that combustion gases are directed into the exhaust system without leakage.

• Provides a precise seal under high-heat conditions.

• Reduces the risk of exhaust leaks, which can cause performance loss and overheating.

• Compatible with Cummins NH855, NT855, and N14 engines.

Upper Gasket Sets for Cummins NH855

An upper gasket set (also known as a top-end gasket set) contains all the essential sealing components needed for cylinder head servicing.

• Includes head gaskets, intake and exhaust gaskets, and related seals.

• Ideal for cylinder head replacement or valve train work.

• Ensures proper combustion sealing and coolant/oil passage integrity.

This is the preferred choice when addressing issues such as blown head gaskets, valve cover leaks, or cylinder head refurbishment on the NH855.

Lower Gasket Sets for Cummins NH855

The lower gasket set contains the gaskets required for servicing the bottom end of the engine, including the oil pan, crankshaft seals, and auxiliary gaskets.

• Covers the oil pan, crankcase, and rear/front structure seals.

• Designed to withstand oil pressure, vibration, and continuous thermal cycling.

• Complements the upper gasket set for a complete overhaul solution.

Oil Pan Gasket for Cummins NH855

The oil pan gasket provides a durable seal between the oil pan and engine block.

• Prevents engine oil leaks from the sump area.

• Made with high-quality materials to resist oil saturation and temperature fluctuations.

• Fits NH855, NT855, and N14 engines.

Replacing the oil pan gasket is often recommended during lower-end servicing or when resealing the crankcase.

Fuel Pump Gasket for Cummins NH855

The fuel pump gasket ensures a leak-free seal at the fuel pump coupling point.

• Critical for maintaining fuel system pressure and efficiency.

• Helps prevent fuel seepage that could cause performance issues or fire hazards.

• Fits NH855 and NT855 engines, along with compatibility across other Cummins heavy-duty platforms (L10, M11, N14, KTA19, KTA38, KTA50, QSK).

Valve Cover Gaskets for Cummins NH855

Valve cover gaskets are necessary to seal the cylinder head’s top end and keep oil contained around the rocker arms and valve train.

Two main styles are available for the NH855:

• New Style Valve Cover Gasket – built with modern synthetic materials for long service life and excellent sealing.

• Old Style Cork Valve Cover Gasket – traditional design offering a reliable seal for vintage configurations.

Both options provide leak-free operation and protect against oil seepage that can cause engine bay contamination.

Oil Seals for Fan Hub – Cummins NH855

The oil seal for the fan hub prevents oil leakage around the fan drive assembly.

• Essential for cooling system reliability.

• Protects bearings and hub components from premature wear due to oil loss.

• Compatible with NH855, NT855, and N14 engines.

Coolant Pump Gaskets and Seals for Cummins NH855

The coolant pump requires multiple gaskets and seals to ensure proper installation and leak-free operation. Diesel Pro Power supplies all necessary sealing components for the NH855 coolant pump, including:

• Water Inlet Connection Gasket – ensures tight sealing at the coolant inlet.

• Mounting Gasket – prevents leaks at the pump housing interface.

• O-Ring Outlet Seal – secures the outlet connection, keeping the coolant system pressurized.

Maintaining these gaskets prevents coolant loss and overheating.

Gasket Sealants & Gasket Makers

For applications where cut gaskets are installed or where additional sealing is required, gasket sprays, sealants, and makers are indispensable. Diesel Pro Power offers professional-grade solutions suitable for Cummins NH855 engines:

• High-Tack Gasket Spray Sealant – holds gaskets in place during installation and ensures improved sealing.

• 3H Gasket Maker – liquid sealant for non-gasketed joints and irregular surfaces.

• High-Strength Red Threadlocker – secures bolts and studs subjected to vibration.

• Silicone Gasket Makers (Sensor Safe & High-Temp RTV) – ideal for applications near sensors and high-heat environments.

• Ultra Blue RTV Silicone – a premium option for flexible sealing in critical areas.

• Non-Hardening Pliable Sealant – flexible compound for applications requiring ongoing movement.

• J-B Weld Cold Weld – strong adhesive for permanent metal-to-metal bonding and emergency gasket repairs.

These solutions enhance gasket installation, extend component life, and provide backup options during emergency field repairs.

Why Choose Diesel Pro Power for NH855 Gaskets

• Comprehensive Coverage: From individual seals to complete gasket sets, every gasket for the NH855 is available in one catalog.

• Quality Materials: All gaskets meet or exceed Cummins OEM standards.

• Proven Reliability: Trusted by more than 40,000 satisfied customers worldwide.

• Expert Support: Our team provides guidance to ensure you get the correct gasket for your engine configuration.

• Fast Shipping: In-stock gaskets and sealants ship quickly to reduce downtime.