E 250 Van V8-6.9L DSL (1985)
Vacuum Pump: Testing and Inspection
A-2 Vacuum Pump Output
Vacuum VS Altitude Chart
^ Disconnect the vacuum pump hose from the brake booster and insert a vacuum gauge. Rotunda Model 059-00008 or equivalent, in the hose end.
Run the engine at normal curb idle and check vacuum. Gauge should read 70kPa (21 inches Hg) at sea level within 30 seconds (refer to graph for
vacuum at other elevations).
^ Is vacuum at or above specified level?
YES -- Go to A4. See: A-4 Vacuum System Check
NO -- Go to A3. See: A-3 System Integrity