4343268 Original Excavator Radiator tank Cover for ZX200

Part number 4343268 is the original radiator water tank cover (pressure cover) provided by Hitachi Construction Machinery for the ZX200 series 20 ton medium-sized hydraulic excavator. This component is mainly used to seal the radiator water inlet, maintain pressure balance in the cooling system, and is a key component to prevent coolant boiling and improve heat dissipation efficiency. Its universal models cover Hitachi ZX200-3, ZX200-5A, ZX200-5G and other ZX200 series excavators, as well as some ZX210, ZX240 platform models. As the core sealing component of the original cooling system, its thread specifications and pressure valve settings are perfectly matched with the radiator water inlet. The use of non-standard auxiliary components is strictly prohibited to avoid pressure imbalance, coolant leakage, or engine overheating.

This product is a spiral pressure cover with pressure valve and vacuum valve. The typical structure is that the outer shell is made of stainless steel or galvanized steel, and the interior integrates pressure springs, rubber sealing rings, and vacuum valve plates. Technical parameters: working pressure 0.9-1.1 bar (approximately 13-16 psi), opening pressure 1.05-1.2 bar, vacuum valve opening negative pressure -0.03-0.06 bar. The pressure valve opens when the system pressure exceeds the standard, allowing excess coolant to flow into the expansion tank; The vacuum valve opens when the system is under negative pressure after cooling, to replenish coolant or air. The sealing ring material is EPDM rubber that is resistant to high temperature and corrosion, and can work for a long time in an environment ranging from -40 ℃ to+120 ℃. The surface of the lid is usually printed with the "HITACHI" logo and pressure value, and the installation method is to tighten clockwise to the buckle lock.

Replacement cycle: Check every 2000 working hours or once a year. If the sealing ring is found to be aging, deformed, cracked, or the pressure valve is stuck, replace it immediately. Disassembly steps: 1 Ensure that the engine is completely cooled (water temperature<50 ℃); 2. Cover the lid with a thick cloth and slowly rotate counterclockwise to the first gear (release residual pressure); 3. After the hissing stops, completely unscrew and remove it. Installation steps: 1 Clean the water inlet threads and sealing surfaces of the radiator; 2. Check if the sealing ring of the new lid is intact; 3. Align the thread and turn it clockwise; 4. Tighten to the locking position of the buckle (with a clear "click" sound to the touch). Attention: 1 It is strictly prohibited to forcefully open the lid under high temperature and pressure conditions; 2. Regularly check the coolant level of the expansion tank; If the coolant frequently overflows or the engine is prone to high temperatures, priority should be given to checking the pressure performance of the water tank cover