Universal Coolant Overflow Tanks/Surge Tanks

Reservoir tanks generally fall into surge tanks, overflow (expansion) tanks, and degas bottles, each designed for specific cooling system architectures. Surge tanks maintain system pressure and act as the highest point in the loop, while overflow tanks simply catch excess coolant during thermal expansion. Material types also vary, including polyethylene, polypropylene, and aluminum, depending on the equipment application and operating temperature.

A coolant overflow tank captures excess coolant that expands due to engine heat, preventing pressure buildup and coolant loss. As the engine cools, it draws coolant back into the radiator, maintaining proper fluid levels. This prevents air pockets, overheating, and radiator cap failure, making it a critical component for maintaining consistent engine temperature across diesel engines, generators, and heavy equipment.

Match the tank to your equipment's make, model, and engine serial number, then cross-reference the OEM part number when possible. Our catalog organizes tanks by manufacturer, including Caterpillar, Peterbilt, Kenworth, and JCB, to simplify identification. If you're unsure, provide your equipment details to our team and we'll confirm compatibility before you order.

Yes, coolant overflow tanks function similarly across diesel and gasoline engines since both rely on liquid cooling systems that experience thermal expansion. However, tank capacity, mounting configuration, and pressure ratings vary by application, so it's important to select a tank specifically designed for your engine type and equipment model rather than assuming universal fit.

Most coolant overflow tanks are manufactured from high-density polyethylene or polypropylene plastic due to their resistance to heat, corrosion, and coolant chemicals but at Radiator Supply House, our tanks are made from heavy duty steel and aluminum. Some heavy-duty industrial and oilfield applications use reinforced or aluminum tanks for added durability under extreme conditions. Material selection affects lifespan, UV resistance, and compatibility with specific coolant formulations.

There's no fixed replacement interval, but tanks should be inspected during routine cooling system maintenance for cracks, discoloration, or brittleness, especially after 5-7 years of service. Replace immediately if you notice leaks, coolant loss without visible external leaks, or a tank that no longer holds pressure, as these signs indicate the plastic has degraded beyond safe use.