Note.
- Engine temperature, auxiliary load and the altitude at which the vehicle is operated affect the amount of vacuum in the intake manifold.
- The vacuum value decreases by approximately 2.7 kPa for every 305 m of altitude above sea level.
1. Disconnect the engine vacuum hose from the brake booster check valve.
2. Install the vacuum gauge on the engine vacuum hose.
3. Start the engine and warm it up to operating temperature at idle speed.
4. With the engine idling and the air conditioning system turned off, check that the vacuum value created by the engine corresponds to the specification:
- Mechanical vacuum pump: 90-95 kPa.
- Electric vacuum pump: 40-70 kPa.
5. Turn off the engine.
6. If the vacuum value created by the engine is normal, proceed to step 10.
7. If the engine vacuum is not within the normal range, check the engine vacuum hose for the following:
- Loose connection to the engine.
- Destruction, deformation or clogging.
- Cracks, cuts and other damage.
8. If any of the above defects are found, replace the vacuum hose and repeat steps 2-4.
9. If no defects are found in the vacuum hose, therefore the problem lies in the source of the vacuum in the engine, it is necessary to check the entire vacuum system.
10. Remove the check valve from the brake booster.
11. Install the check valve on the vacuum hose.
12. Install a vacuum gauge on the check valve.
13. Start the engine and warm it up at idle speed to operating temperature.
14. Turn off the engine.
15.Make sure that the vacuum value created by the engine complies with the specification:
- Mechanical vacuum pump: 90-95 kPa.
- Electric vacuum pump: 40-70 kPa.
16. If the vacuum value created by the engine is normal, go to step 18.
17. If the vacuum value created by the engine is not within the norm, replace the vacuum booster check valve with a new one, then repeat steps 11-15.
18. Check the vacuum booster check valve gasket for the following:
- Loose connection to vacuum booster.
- Deformation or contamination.
- Cracks, cuts and other damage.
19. If any of the listed defects are detected, replace the check valve gasket with a new one.
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