Pic. 2.6. Special adapter for connecting the radiator cap to the tester
Use a special adapter to connect the radiator cap to the tester (pic. 2.6).
Increase the pressure until the pressure gauge needle stops (valve opening pressure).
Main valve opening pressure: 83–110 kPa.
Vacuum valve opening pressure: 7 kPa.
Verify that the set pressure of the bonnet valves is either within or slightly above the rated value.
Replace the radiator cap if the valve opening pressure is below the rated value.
Note. Make sure the radiator cap is clean before checking, as rust or other foreign matter on the cap seal may cause the pressure gauge to read incorrectly.