Airtightness Inspection

Use a handy vacuum pump to check.

Fig 1: Identifying Valve Using Vacuum Pump

Courtesy of NISSAN MOTOR CO., U.S.A.

When connected to booster side (1): Vacuum decrease should be within 1.3 kPa (10 mmHg, 0.39 inHg) for 15 seconds under a vacuum of -66.7 kPa (-500 mmHg, -19.69 inHg) 

When connected to engine side (2): No vacuum will be applied