Coolant Overflow Tanks and Reservoirs

Yes, the overflow tank should be filled to the manufacturer-specified level, typically marked with 'low' and 'full' lines, when the engine is cold. Overfilling can cause coolant to be expelled during operation, while underfilling risks air entering the cooling system and reduced heat transfer efficiency.

Most overflow tanks and reservoirs are constructed from high-density polyethylene (HDPE) plastic or aluminum, chosen for resistance to heat, pressure, and coolant chemical exposure. Heavy-duty applications like construction equipment and commercial trucks often use reinforced plastic or metal tanks rated for higher operating pressures and temperatures.

Common signs include visible cracks, coolant leaks around the tank, discolored or contaminated coolant, a consistently low coolant level despite topping off, or a damaged cap that fails to hold system pressure. Replacing a failing tank promptly prevents overheating and potential engine damage.

Yes, reservoir and surge tanks are typically designed to match the mounting configuration, capacity, and pressure rating of a specific engine or cooling system. Radiator Supply House stocks OEM-compatible tanks for brands including Caterpillar, Kenworth, Freightliner, JCB, and Doosan to ensure proper fitment.

While some tanks share similar designs, capacity and mounting requirements vary significantly between construction equipment, commercial trucks, oilfield machinery, and RVs. It's important to match the tank to your specific make and model rather than assume universal compatibility.

Pricing varies by application and capacity, generally ranging from around $311 for standard truck and construction equipment tanks up to $1,916 for specialized oilfield or heavy machinery reservoirs. RV and motorhome reservoir tanks fall within a comparable range depending on vehicle size and manufacturer.