Cummins QSB 4.5 Parts for Canada - Gasket Section

Cummins QSB 4.5 Engine Gasket Catalog

The Cummins QSB 4.5 is a high-performance marine and industrial diesel engine known for its compact size, reliability, and ability to deliver exceptional torque in a variety of demanding applications. Whether powering commercial vessels, industrial machinery, or auxiliary systems, the QSB 4.5 is built to operate under continuous loads and in harsh environments. To maintain peak performance, one of the most critical aspects of engine maintenance is the integrity of its sealing systems — and that’s where a complete and well-sourced gasket catalog comes into play.

Gaskets and sealing components ensure that vital fluids such as oil, coolant, and fuel remain contained, preventing leaks that could cause efficiency losses, environmental hazards, or costly engine damage. From upper and lower gasket sets used in overhauls to individual seals for specific components like the raw water pump or oil cooler, each part in this section is designed to meet Cummins OEM specifications for fit, durability, and performance.

Below, you’ll find a complete breakdown of gaskets, seals, and sealants available for the QSB 4.5, with details on their function, compatible components, and role in maintaining engine reliability.

Gasket to Mount the Marine Raw Water Pump

The marine raw water pump is essential to your QSB 4.5’s cooling system, drawing in seawater to regulate engine temperatures. The gasket to mount the raw water pump ensures a leak-free seal between the pump and the engine housing. Without this gasket, even the smallest gap could allow water intrusion into unintended areas or lead to pump inefficiency. Manufactured to withstand constant exposure to moisture, salt, and heat, this gasket uses marine-grade materials to prevent premature degradation.

Lower Gasket Set for Cummins QSB 4.5

When rebuilding the lower section of your engine — which includes the crankcase, oil pan, and related assemblies — a lower gasket set is essential. The Cummins QSB 4.5 lower gasket set contains all necessary seals for components located below the cylinder head, ensuring complete containment of oil and coolant in these areas. Each gasket is precision-cut for a perfect fit, reducing the chance of leaks during extended service intervals.

Upper Gasket Set for Cummins QSB 4.5

The upper gasket set is designed for the top-end rebuild of your engine, including the cylinder head, intake, and exhaust manifolds. It includes seals for the combustion chamber, preventing gases from escaping and ensuring maximum compression. Properly installed upper gaskets contribute directly to engine efficiency, fuel economy, and reduced emissions.

Gasket for Oil Pick-Up Tube

The oil pick-up tube draws oil from the pan into the lubrication system. A secure gasket at the pick-up tube connectionis critical to prevent air intrusion, which can cause oil starvation and damage internal components. This gasket is compatible with Cummins 4B, 6B, ISB, and QSB engines, making it a versatile choice for mixed fleets.

Intake Manifold Cover Gasket

The intake manifold cover gasket seals the interface between the intake manifold cover and the cylinder head. It prevents air leaks that could upset the air-fuel mixture and cause performance loss. Built to resist the high temperatures of the intake system, this gasket also protects against warping or sealing failure.

O-Ring for Aftercooler

An aftercooler O-ring seals the coolant or air passages within the aftercooler assembly. For the QSB 4.5, this is crucial in preventing coolant leaks into the intake path or loss of pressurized air, both of which can reduce power output and efficiency.

Valve Cover Gasket

The valve cover gasket keeps oil inside the cylinder head area, preventing leaks while protecting rocker arms, valve springs, and other top-end components from contamination. A fresh valve cover gasket is a must whenever servicing the valve train.

Fuel Transfer Pump Gasket

This small but vital fuel transfer pump gasket prevents fuel leaks at the pump mounting surface. It helps maintain consistent fuel pressure, which is critical for injection system efficiency and combustion stability.

Fuel Injection Pump Gasket

The fuel injection pump gasket ensures a tight seal at the pump mounting interface. Any leakage here can lead to fuel delivery issues, reduced power, and increased emissions.

Gasket for Oil Cooler Cover

Oil cooler cover gaskets maintain separation between oil passages and coolant circuits in the oil cooler assembly. The QSB 4.5 uses these gaskets to prevent cross-contamination of fluids, which could cause catastrophic engine failure if not properly sealed.

Turbo Oil Drain Gasket

The turbo oil drain gasket seals the oil return line from the turbocharger to the engine. Preventing leaks here ensures that oil is efficiently recycled without loss or contamination.

Oil Cooler Core Gasket

The oil cooler core gasket provides a durable metal-seal connection for the oil cooler core. Designed to withstand high pressure and fluctuating temperatures, it keeps oil flow consistent and leak-free.

Water Pump Seal Ring

A seal ring for the water pump prevents coolant leakage at pump connections, ensuring that coolant flow remains at optimal pressure throughout the cooling circuit.

Thermostat Seal

The thermostat seal prevents coolant leakage around the thermostat housing. This ensures accurate temperature regulation and prevents overheating or overcooling.

Gasket Sealants & Compounds for Cummins QSB 4.5

In addition to traditional gaskets, certain applications require gasket makers, RTV silicones, and high-temperature sealants. These products provide flexible sealing solutions where paper or metal gaskets are not suitable. They also serve as supplementary sealing layers for extra leak prevention.

• Hi-Temperature Jointing Compound – Ideal for turbocharger applications, withstanding temperatures up to 760°C.

• Gasket Spray – High Tack Sealant – Holds cut gaskets in place during installation.

• 3H Gasket Maker – Liquid sealant for flexible joints.

• Threadlocker Red – High-strength compound for securing threaded fasteners.

• Silicone Sensor Safe RTV – For applications near sensors without causing corrosion.

• Cold Weld Epoxy – Repairs and seals cracks in metal surfaces.

• High-Temp RTV Silicone – For extreme heat areas such as exhaust manifolds.

• Ultra Blue RTV Silicone – Flexible, sensor-safe sealant for a wide range of applications.

• Non-Hardening Pliable Sealant – Flexible and vibration-resistant for dynamic joints.