The locking screw marked as K 73033 is a seemingly small but indispensable element in the secure fastening of the cooling water pump casing in the ZV40/48 engine. Designed to resist vibration and pressure fluctuations, this screw helps maintain a tight, leak-free seal around the pump housing. Precision manufacturing ensures it stays in place even during prolonged engine operation. By preventing coolant leakage and preserving pressure integrity, the locking screw contributes to the stability and efficiency of the engine’s cooling system.