Common faults are leaks, it mainly caused by corrosion perforations and mechanical damage. A heat sink penetration test can be performed using a seal tester. Removing the radiator cap and inject coolant into the cooling system when checking for leaks. Install the radiator cap tester and apply a pressure of 117.6 kPa to the cooling system using the radiator cap tester. Then, check the radiator upper and lower water chambers and radiator core, and see if there is any leak at the pump and hose connections. If there is a leak, repair it with solder. If the leak is in the upper and lower water chambers, the broken joint can be filled with a thin copper cover. For example, a water pipe leaking outside the radiator core can be repaired with a tip iron or a thin copper sheath. Internal water pipes leak and are often repaired by acetylene gas welding.