4396809 Original Excavator Water tank Cover for ZX200-5G

The original water tank cover part number 4396809 is a cooling system pressure sealing component provided by Hitachi Construction Machinery for the ZX200-5G series hydraulic excavator (with a total working weight of 20.3 tons and engine model Isuzu CC-6BG1T). This water tank cover is mainly used for radiators or expansion tanks, maintaining pressure balance inside the cooling system through pressure valves and vacuum valves to prevent coolant boiling or air from entering. Its universal models usually cover excavators of the ZX200-3, ZX200-5A, ZX210, ZX240 series and similar tonnage. As the original pressure cap, it is precisely matched with the thread specifications of the radiator filling port. The use of non-standard spare parts is strictly prohibited to ensure sealing reliability and safe operation of the system.

This product is an original pressurized water tank cover, usually made of galvanized steel sheet stamping or engineering plastic (PPS/PA66). Typical technical parameters: opening pressure of 93-123kPa, vacuum valve opening pressure of -5-15kPa, thread specifications of M48 × 1.5 or M52 × 1.5, working temperature range of -40 ℃ to+130 ℃. The interior of the cover is integrated with rubber sealing rings (EPDM material) and a dual valve structure (pressure valve+vacuum valve), which can effectively maintain system pressure, prevent coolant evaporation loss, and eliminate air. This cover complies with JIS B 8243, GB/T 8243.1 and other standards, is corrosion-resistant, vibration resistant, and suitable for environments with ethylene glycol based coolant.

Inspection cycle: It is recommended to check the sealing ring of the cover for aging and cracking, and the pressure valve spring for failure every 500 working hours; Test the opening pressure every 1000 working hours (using a dedicated pressure tester). Installation points: 1 Clean the threads of the radiator filling port (remove scale and rust); 2. Confirm the direction of the cover (usually with "MAX" or arrow markings aligned with the radiator); 3. Tighten until there is a "click" sound (indicating that the lock is in place); 4. Excessive tightening is strictly prohibited (torque usually 15-25N · m). Fault diagnosis: If there is coolant leakage, abnormal system pressure, or high water temperature, it is necessary to check whether the sealing ring of the water tank cover is damaged, the valve plate is adhered, or the spring is fatigued; If the deviation of the stress test value is greater than 20%, it should be replaced immediately.