Diesel Data: Automotive Repair

Alternator Driven Vacuum Pump


1. Connect a suitable vacuum gauge to vacuum pump inlet.
2. With parking brake fully applied and transmission in Park, start engine and operate at 600-5000 RPM while noting vacuum gauge.
3. Vacuum gauge should maintain a reading of 25.6 inches Hg. If vacuum does not meet specifications, the pump should be disassembled and inspected and serviced as necessary.