SINOTRUK HOWO A7 Model T7H SITRAK C7H C9H TX G7S Truck Body Parts New WG9412531321 Expansion Tank for Truck

The Coolant Expansion Tank Assembly (Part No. WG9412531321) is a critical component of the engine cooling system in Sinotruk (China National Heavy Duty Truck Group Co., Ltd.) heavy-duty trucks. Officially named the Water Expansion Tank or Coolant Reservoir, it plays a vital role in maintaining stable thermal performance by accommodating coolant expansion and contraction during engine operation.

Mounted within the engine compartment, this tank ensures safe pressure regulation, effective air-liquid separation, and real-time monitoring of coolant levels — preventing overheating, cavitation, and catastrophic engine failure such as cylinder liner "scuffing" or head gasket damage.