All Others - Functional Test
- Inspect check valve whenever working on system. If pump was inoperative and had signs of exhaust gases reaching pump, a failed check valve would be indicated.
- Seal off vacuum supply to diverter valve by pinching hose. Hold for at least one second, then release hose. Air should now be exhausting from bottom of diverter valve. It should do so for about four seconds. Replace diverter valve if air does not exhaust.