Which technician is correct regarding cooling system testing: Technician A claims that leaks should be tested using a pressure tester, while Technician B says freezing and boiling points can be tested with a thermometer?

In assessing the claims made by the technicians regarding cooling system testing, it becomes clear that neither technician's statements are accurate relative to standard practices in engine repair.

Technician A suggests that leaks should be tested using a pressure tester, which is indeed a common and effective method for identifying leaks in a cooling system. A pressure tester allows the technician to pressurize the cooling system and observe for any drops in pressure that would indicate a leak. However, it’s important to note that this method is only partially complete without considering additional signs of leaks, such as visual inspections or other diagnostic tools.

On the other hand, Technician B claims that freezing and boiling points can be accurately tested with a thermometer. While a thermometer can measure the temperature of the coolant, it cannot effectively determine the freezing and boiling points, which are crucial for assessing the coolant's effectiveness. Testing these points typically requires a coolant hydrometer or refractometer, both of which are designed to measure the concentration of the coolant mixture, particularly ethylene glycol or propylene glycol, and derive the corresponding freezing and boiling points from that concentration.

Thus, neither technician fully represents correct practice regarding the methods of testing for leaks or assessing coolant properties. This means that the answer accurately suggests that neither technician is correct