Radiator Cap Pressure Test

Use an adapter to attach the cap to the tester.

Fig 1: Radiator Cap Pressure Test
Courtesy of KIA MOTORS AMERICA, INC.
Increase the pressure until the indicator of the gauge stops moving.
Main valve opening pressure:

86.1-124.5 kPa (0.98-1.27 kg/cm²

13.94-18.069 psi)

Main valve closing pressure:

83.4 kPa (0.85 kg/cm² 12.1 psi)
Check that the pressure level is maintained at or above the limit.
Replace the radiator cap if the reading does not remain at or above the limit.

NOTE: Be sure that the cap is clean before testing, since rust or other foreign material on the cap seal will cause an improper indication.