## Charging System

#### Alternator and Vacuum Pump Overhaul (cont'd)

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Vacuum pump

The vacuum pump performance test should be conducted by means of a vacuum pump oil tester as follows.

1. Open the oil supply valve and make sure that oil flows out. Fill the vacuum pump tester with a suitable amount of engine oil (SAE #10 to #30). Then set the vacuum pump tester at a place a little higher than the alternator so as to facilitate oiling.

1. Increase the alternator speed gradually and make sure that oil flows through oiling hose and the vacuum pump to the exhaust hose.

1. After making sure of full circulation of oil, close the release valve and measure the vacuum characteristic by a vacuum gauge and a clock.

1. Measure the vacuum drop (air-tightness) characteristic. To be more specific, stop the alternator at the vacuum of -53.3 kPa (-400 mmHg) and make sure the vacuum drop after 15 sec. is -2.67 kPa (-20 mmHg) or less.

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