InspectionQuestion 28 of 60
What is the correct way to begin the air brake check for build-up rate in a dual air system?
a.Drain all the tanks completely first
b.With the engine at operating rpm, check that pressure builds from about 85 to 100 psi within about 45 seconds
c.Apply the parking brake and rev the engine
d.Disconnect the trailer air lines
Explanation
In a dual air system, with the engine at operating rpm, the pressure should build from about 85 to 100 psi within about 45 seconds. If air pressure does not build up fast enough, your pressure may drop too low during driving, requiring you to stop and wait to build air. Slow build-up indicates a problem to be fixed.
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