Komatsu Forklift Radiator Cap 3EB0421130 – Electric Diesel Trucks

Komatsu Forklift Radiator Cap 3EB0421130 — Electric & Diesel Trucks

This OEM-spec radiator cap (part number 3EB0421130) is a direct-fit replacement for Komatsu electric and diesel forklift trucks. The radiator cap is the pressure seal at the cooling system’s highest point — it maintains system pressure (typically 0.9 bar) to raise the coolant’s boiling point, preventing boil-over during peak engine temperatures. A weak or failed cap that doesn’t hold rated pressure causes coolant loss through the overflow, air pockets in the cylinder head, and eventual overheating damage that is often misdiagnosed as a water pump or thermostat failure.

The 3EB0421130 cap features a spring-loaded pressure valve and vacuum relief valve. The pressure valve opens at the rated pressure to vent excess pressure to the overflow tank. The vacuum valve opens during engine cooldown to draw coolant back from the overflow tank into the radiator — if this valve sticks, the upper radiator hose collapses under vacuum and the cooling system develops air pockets. Backed by a 3-month warranty from TOOMOTOO brand, manufactured in Tianjin, China.

Compatible with Komatsu electric and diesel forklift trucks using this radiator cap specification. Browse our forklift radiator cover selection for other models.

Technical Specifications

Always inspect the radiator filler neck for corrosion before installing a new cap. Send us your Komatsu model for confirmed fitment →