freightliner Cargo Manual page 100

With the service brakes released, shut down
the engine, wait one minute and note the air
pressure gauge reading. Observe the air
pressure drop in psi (kPa) per minute.
Charge the air system until cutoff pressure
of 125 psi (862 kPa) is reached. With the
parking brakes released and the service
brake applied, shut down the engine, wait
one minute and note the air pressure gauge
reading. Observe the air pressure drop in psi
(kPa) per minute.
If leakage exceeds the limits shown in
Table 9.1, repair all areas of leakage before
driving the vehicle.
WARNING
Before operating the vehicle, be sure the spring
parking brakes on the vehicle pass the above tests.
Otherwise an unexpected parking brake application
could occur, causing some loss of vehicle control
and possibly resulting in serious personal injury.
40. Test the service brakes before leaving the lot.
When starting to move the vehicle and before pick-
ing up speed, test the brakes with the foot valve
and parking brake valve to be sure they will bring
the vehicle to a safe stop.
Pretrip Inspection and Daily Maintenance
Maximum Allowable Service Brakes Air Leakage
Description
Truck or Tractor Only
Truck or Tractor w/Single Trailer
Truck or Tractor w/Two Trailers
Table 9.1, Maximum Allowable Service Brakes Air
Leakage
41. Test the parking brakes on a 20 percent grade.
Pull the parking brake control valve knob or apply
the hand brake with the vehicle on a 20 percent
grade. If the parking brakes do not hold the vehicle,
repair the parking brake system.
Air Leakage in psi
(kPa) Per Minute
Released Applied
2 (14) 3 (21)
3 (21) 4 (28)
5 (35) 6 (42)
9.22