Cars with gasoline engines
- Excess pressure valve - opens at a pressure of 81.4–108 kPa
- Vacuum valve spring; the vacuum valve opens at a vacuum of minus 6.86 kPa
Cars with diesel engines
- Excess pressure valve - opens at a pressure of 107.9±14.7 kPa
- Excess pressure valve - closes at a pressure of 83.4 kPa
Examination
1. Check the spring and mating surfaces of the valve for damage.
2. Attach the radiator cap to the radiator cap tester.
3. Apply pressure until the pointer needle stabilizes.
4. After 10 seconds, check the pressure, which should not change. Replace the radiator cap if necessary.