1-21. Compressed Air System Operation
The compressed air system consists of an air compressor, air governor and air reservoirs,
and the trailer airbrake components. The compressed air system supplies air to the air-
hydraulic brake cylinder, windshield wiper motors, horn, and air supply valves. Air from
the supply valves can be used to inflate the tires. When air pressure in the air reservoir
tanks is low, a buzzer is set off in the drivers compartment to warn the driver.