Air Bypass Valve
- With engine at normal operating temperature, disconnect air bypass-to-air control valve hose at bypass valve. Remove vacuum hose. Start engine and check for air pump pressure at vent port. System output should be felt at vent port. No output should be present at disconnected port.
- Apply 10 in. Hg to vacuum nipple. Air pump pressure should be felt at disconnected port and not at vent port. If valve does not operate as described and air pump and diverter check valve are not defective, replace air bypass valve.