Air Break Practice Test

Results

#1. With the engine idling at _________, air pressure must rise from 85 to 100 psi within two minutes.

800–1200 rpm

600–900 rpm

100–500 rpm

100–1200 rpm

To test the air pressure build-up time, start by reducing the pressure to below 552 kPa (80 psi). If the vehicle has a trailer attached, ensure the trailer supply valve is closed (pulled out). With the engine idling at 600–900 rpm, the air pressure must rise from 587 kPa (85 psi) to 690 kPa (100 psi) within two minutes.