Attention:
- The vacuum created is affected by engine temperature, the operation of attachments and altitude;
- The vacuum created is reduced by approximately 3 kPa for every 305 m above sea level.
1. Disconnect the vacuum hose from the check valve of the vacuum booster.
2. Connect a vacuum gauge to the hose.
3. Start the engine at idle and warm it up to operating temperature.
4. If on, turn off the air conditioner. With the engine running at idle, read the vacuum gauge. Nominal depression 47-68 kPa.
5. Turn off the ignition.
6. If the vacuum generated is normal, go to step 10.
7. If the vacuum is low, evaluate the condition of the vacuum hose and check the reliability of its connection to the engine.
8. Eliminate the found defects and repeat the operations in steps 2-4.
9. If there are no hose defects, check the condition of the engine.
10. Remove the vacuum booster check valve.
11. Connect the valve to the engine vacuum hose.
12. Connect a vacuum gauge to the valve.
13. Run the engine to idle.
14. After stabilization of the vacuum gauge readings, turn off the ignition.
15. Check how the check valve holds the vacuum.
16. If vacuum is maintained, go to step 18.
17. If vacuum is not maintained, replace check valve and repeat steps. 11-15.
18. Check the check valve o-ring, look for signs:
- loose fit in the vacuum booster;
- deformation or contamination;
- keratinization, cuts and other defects.
19. At detection of defects replace a sealing ring.