A vehicle in for repair has a burst upper radiator tank. Technician A says thermostat that was stuck in the open position could be the cause. Technician B says that a faulty radiator pressure cap could be the cause. Who is correct?

Technician B

Explanation:

A thermostat being stuck in an open position allows coolant to constantly circulate through the radiator which will cause a drop in the temperature of the engine. Hence, thermostat being stuck in an open position has nothing to do with burst upper radiator.

On the other hand, a radiator cap controls the pressure within the radiator which needs to be kept constant in order prevent overheating or damage to the radiator itself.

Therefore, technician B is correct.