For 1990-2009 cars only
- Remove the engine vacuum hose from the vacuum brake booster.
- Install a vacuum gage to the engine vacuum hose.
- Start the engine. Verify the transmission is in Park or Neutral.
- Allow the engine to idle until the engine reaches normal operating temperatures.
- Measure the engine vacuum.
- Turn the ignition OFF.
- If the engine vacuum reading meets or exceeds the minimum specification, verify the check valve operates properly.
- If the engine vacuum reading is less than the minimum specification, inspect the vacuum booster pipe and hoses for the following conditions:
- Replace any defective vacuum booster pipe or hose. Refer to Vacuum Brake Booster Check Valve and/or Hose Replacement .
- If none of these conditions exist on the pipe and hoses, then there is an engine vacuum source problem. Inspect the engine vacuum system. Refer to Diagnostic Starting Point - Engine Controls in Engine Controls -- 2.0L or to Diagnostic Starting Point - Engine Controls in Engine Controls -- 2.5L.
Specification
The minimum engine vacuum is 17 in Hg (57.6 kPa)
| • | Loose connection to the engine |
| • | Collapse, deformation or contamination |
| • | Cracks, cuts, dry-rot |
Important: If the engine does not produce proper vacuum, the vehicle will have driveability conditions in addition to the brake assist condition.
