STEP 2. Check the radiator cap valve opening pressure.

WARNING: This page is about a different car, the 2003 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Be sure that the cap is clean before testing. Rust or other foreign material on the cap seal will cause an improper reading.

Use a cap adapter to attach the cap to the tester.
Increase the pressure until the gauge indicator stops moving.
Minimum limit: 83 kPa (12 psi)

Standard value: 93-123 kPa (14-18 psi)

Fig 1: Checking Radiator Cap Valve Opening Pressure

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Does the reading remain at or above the minimum limit?

YES : Go to Step 3.
NO : Replace the radiator cap. Then go to Step 5 .