Brake System Vacuum Source Test STS-V

1. Disconnect the brake booster vacuum hose from the engine intake manifold.
2. Install a vacuum gage to the engine intake manifold vacuum port.
3. Start the engine and allow the engine to idle until normal operating temperatures are reached.
4. Check to see if the engine vacuum reading is within the specified normal engine vacuum range.

Specification
47-68 kPa (14-20 in Hg)

5. Turn the ignition OFF.
6. If the engine vacuum reading is within the specified normal range, proceed to step 8.
7. If the engine vacuum reading is NOT within the specified normal range, then there is an engine vacuum source problem. Check the engine vacuum system.
8. Install the booster vacuum hose to the intake manifold.
9. Remove the brake booster vacuum hose with fitting from the booster.
10. Install the vacuum gage to the vacuum hose assembly fitting.
11. Start the engine and allow the engine to idle until normal operating temperatures are reached
12. Check to see if the venturi valve vacuum reading is within the specified normal venturi valve vacuum range.

Specification
64-85 kPa (19-25 in Hg)

13. Turn the ignition OFF.
14. If the venturi valve vacuum reading is within the specified normal venturi valve vacuum range, proceed to step 18.
15. If the venturi valve vacuum reading is NOT within the specified normal venturi valve vacuum range, inspect the venturi valve vacuum hose assembly for the following conditions:

•	Tight connection to the engine

•	Tight connections to the venturi valve

•	Tight connection to the air cleaner outlet duct

•	Collapse, deformation, or contamination

•	Cracks, cuts, dry-rot

16. If any of these conditions were found with the booster vacuum hose assembly, replace the booster venturi valve vacuum hose assembly, then repeat steps 10-12.
17. If none of these conditions were found with the booster vacuum hose assembly, then the venturi valve requires replacement. Replace the booster venturi valve vacuum hose assembly, then repeat steps 10-12.
18. Check to see if the venturi valve vacuum reading is maintained within the specified normal venturi valve vacuum range.

Tighten
64-85 kPa (19-25 in Hg)

19. If the venturi valve vacuum reading is maintained within the specified normal venturi valve vacuum range, proceed to step 21.
20. If the venturi valve vacuum reading is NOT maintained within the normal specified normal venturi valve vacuum range, replace the booster venturi valve vacuum hose assembly, then repeat steps 10-12.
21. Inspect the brake booster vacuum hose fitting grommet for the following conditions:

•	Firm connection to the vacuum brake booster

•	Deformation or contamination

•	Crack, cuts, dry-rot

22. If any of these conditions were found with the vacuum hose fitting grommet, replace the grommet.

Brake System Vacuum Source Test STS

1. Disconnect the engine vacuum hose from the vacuum brake booster check valve.
2. Install a vacuum gage to the engine vacuum hose.
3. Start the engine and allow the engine to idle until normal operating temperatures are reached.
4. Check to see if the engine vacuum reading is within the specified normal engine vacuum range.

Specification
47-68 kPa (14-20 in Hg)

5. Turn the ignition OFF.
6. If the engine vacuum reading is within the specified normal range, proceed to step 10.
7. If the engine vacuum reading is NOT within the specified normal range, inspect the engine vacuum hose for the following conditions:

•	Tight connection to the engine

•	Collapse, deformation, or contamination

•	Cracks, cuts, dry-rot

8. If any of these conditions were found with the engine vacuum hose, replace the hose, then repeat steps 2-4.
9. If none of these conditions were found with the engine vacuum hose, then there is an engine vacuum source problem. Check the engine vacuum system.
10. Remove the vacuum brake booster check valve from the booster.
11. Install the check valve to the engine vacuum hose.
12. Install the vacuum gage to the check valve.
13. Start the engine and allow the engine to idle until normal operating temperatures are reached.
14. Turn the ignition OFF.
15. Check to see if the engine vacuum reading is maintained within the specified normal engine vacuum range.

Specification
47-68 kPa (14-20 in Hg)

16. If the engine vacuum reading is maintained within the specified normal range, proceed to step 18.
17. If the engine vacuum reading is NOT maintained within the specified normal range, replace the brake booster check valve, then repeat steps 11-15.
18. Inspect the brake booster check valve grommet for the following conditions:

•	Firm connection to the vacuum brake booster

•	Deformation or contamination

•	Cracks, cuts, dry-rot

19. If any of these conditions were found with the check valve grommet, replace the grommet.