Heavy-Duty Truck Radiator & Coolant Filler Caps

The radiator filler cap (or coolant pressure cap) is one of the most essential, yet often overlooked, components in your truck's cooling system. This small part is responsible for much more than simply covering the radiator neck—it is the primary component that dictates and maintains the system's operating pressure.

A failed or incorrect radiator cap is a direct route to major cooling system issues:

• Overheating: If the cap fails to hold the correct pressure, the coolant boils at a lower temperature, leading to rapid overheating.

• Coolant Loss: A damaged seal allows coolant to escape when the engine is hot.

• System Damage: Incorrect pressure can stress hoses, gaskets, and even the radiator itself.

Why the Correct Expansion Tank Cap Matters

All radiator caps are designed specifically for your truck model and engine.  It is critical to replace your cap with one that matches the original equipment manufacturer (OEM) specifications for your truck. Using the wrong cap can lead to failure.

We stock pressure-tested, radiator caps for all major heavy-duty truck makes and models, including:

• Freightliner, International, Kenworth, Peterbilt, Volvo and Mack

Shop our selection of Pressure-Tested Radiator & Coolant Filler Caps now!