Vacuum Pump: Testing and Inspection

1. Disconnect vacuum hose from pump, then connect a suitable vacuum gauge to pump.
2. Disconnect pump electrical connection, then connect terminal No. 1 to battery positive and connect terminals No. 2 and No. 3 to ground.
3. Connect terminal No. 4 to ground, vacuum gauge should read 15.7 inch Hg or more.
4. Disconnect terminal No. 2 from ground, vacuum gauge should read 6 inch Hg or less.
5. Reconnect terminal No. 2 to ground and disconnect terminal No. 3 from ground, vacuum gauge should read 6 inch Hg or less.