Radiator Leakage Test

WARNING: This page is about a different car, the 2021 Kia Soul. However, it is still accessible from the selected car via links, so may be relevant.

Wait until engine is cool, then carefully remove the radiator cap and fill the radiator with engine coolant, then install it on the pressure tester.

Courtesy of KIA MOTORS AMERICA, INC.
Apply a pressure of 93.16 - 122.58 kPa (0.95 - 1.25 kg/cm² , 13.51 - 17.78 psi) to the pressure tester.
Inspect for engine coolant leaks and a drop in pressure.
If coolant leak or pressure drop is occur, replace the part.
NOTE: Check for engine oil in the coolant and/or coolant in the engine oil.