Expansion Tank DNM Denko ST8RC (MPN SDNM0033) – compact coolant/overflow reservoir

DNM Denko ST8RC expansion tank is a compact coolant overflow reservoir designed for cooling systems that require an external sealed container for thermal expansion and temporary fluid storage. The unit provides a dedicated location to collect excess coolant when engine temperature rises and returns fluid to the system as it cools. Its compact form factor allows installation in confined engine bays or on small engines where space is limited.

Advantages

The expansion tank offers a simple, reliable solution for managing coolant overflow and maintaining correct coolant level in closed or semi-closed cooling systems. Its sealed design reduces the risk of contamination and helps preserve system pressure balance. The compact dimensions and standardized inlet/outlet arrangement make it suitable for retrofit or replacement applications without extensive modification.

Suitable for

• Automotive cooling systems requiring an external expansion/overflow reservoir
• Small engine applications with limited installation space
• Replacement of worn or damaged external coolant reservoirs
• Retrofit projects where a compact, sealed tank is needed

Key specifications

• Function: coolant expansion and overflow reservoir
• Design: compact external tank suitable for confined spaces
• Material: durable thermoplastic construction for fluid compatibility and corrosion resistance
• Connection type: standard inlet/outlet ports for coolant hose attachment
• Sealing: sealed top to reduce contamination and maintain pressure balance

How to use

Install the expansion tank in a stable, upright position within reach of the cooling system's filler neck or hose connection. Connect the inlet and outlet hoses securely using appropriate clamps, ensuring leak-free joints. Fill the system with the recommended coolant to the prescribed level, then run the engine until operating temperature is reached to allow air to purge and coolant to circulate between the radiator and the expansion tank. Check for leaks and confirm coolant level after the system cools, topping up if necessary.

Usage recommendations

Use coolant and additives recommended by the vehicle or engine manufacturer. Inspect hose connections and the tank body periodically for signs of wear, cracks, or leaks, and replace the tank if damage or persistent leakage is observed. When installing in confined spaces, verify routing to avoid contact with hot components or moving parts.