Combination vehicles Flashcards
Which shut-off valves should be open and which closed?
Open the Emergency shut-off valve
Shut-off valve for trailer and dollies are in open position.
How can you test that air flows to all trailers?
If you open the emergency line shut-off valve at the rear of the last trailer. You should hear air escaping, showing the entire system is charged. If no air escapes the system is not charged.
How can you test the tractor protection valve?
Step on and off the brake pedal several times. The trailer air supply control should pop out (or go from “normal” to “emergency” position) when the air pressure falls into the pressure range specified by mfg.
How can you test the trailer emergency brakes?
Pull gently on the trailer with the tractor to check that the trailer emergency brakes are on.
. How can you test the trailer service brakes?
Check for normal air pressure, release the parking brakes, move the vehicle forward slowly, and apply trailer brakes with the hand control (trolley valve), if so equipped.
