Ford F-650 Owner's Manual page 13

Engine starting (parking brake applied)
Air brakes Verify air brake operation in the following manner
(chock the wheels, if necessary. Push in the
parking brake and on tractors, also push in the
tractor parking brake knob):
1. Verify the air compressor or governor cut-out
pressure is approximately 120 psi (827 kPa).
2. Turn off the engine, then turn the key back to
the on position, without starting the engine.
3. Without the brake pedal applied, note the air
pressure drop for one minute; it should be less
than 2 psi (14 kPa) for single vehicles and 3 psi
(21 kPa) for combination vehicles.
4. Press and hold the brake pedal with 90 psi
(621 kPa) or more and make sure there is no
more than a 3 psi (21 kPa) per minute leak; for
combination vehicles, no more than 4 psi
(28 kPa) per minute.
5. Pump the brake pedal to deplete the system of
air pressure. The warning light and chime should
activate at 57 psi (393 kPa).
6. Pump the brake pedal and make sure the
parking brake and trailer parking brake knobs
pop out at 20 psi (138 kPa) or higher.
Automatic Inspect the automatic transmission fluid with the
transmission fluid engine idling at normal operating temperature
and the parking brake applied. If fluid needs to
be added, refer to Transmission fluid in the
Maintenance and Specifications chapter.
2012 F-650/750 (f67)
Supplement, 2nd Printing
USA (fus)
Vehicle Inspection Guide
13