T4 ASE- Brakes Practice Questions with Complete
Solutions Assured Success
The governor can be integral or separate from the air compressor. T/F - Correct
AnswersTrue
Governor cut-out is adjustable, while cut-in can not be adjusted. T/F? - Correct
AnswersTrue.
Typical governor cut-out is approxamtely? - Correct Answers120-130 PSI.
What valve does the air compressor use to discharge the air to the air dryer? - Correct
AnswersDischarge valve.
Air compressors are commonly gear driven, but can be ________ driven in rare occasions.
- Correct AnswersBelt.
Air compressors can be cooled via _______ and/or ______ and are lubricated with
______? - Correct AnswersEngine coolant / Air / Engine Oil
Air dryers have two cycles. What are they? - Correct AnswersPurge and Charge.
What occurs during the purge cycle of an air dryer? - Correct AnswersWhen the governor
reaches cut-out pressure, the signal pressure from the governor's unloader valve operates
the purge valve on the dryer. This removes large contaminants, solid and liquid, from the
dryer.
During the purge cycle of an air dryer, governor cut-out is reached. Technician A states
that the cutoff piston in the dryer blocks the compressors supply air. Technician B states
that the dessicant in the dryer removes about 95% of the moisture in the air. Who's
correct? - Correct AnswersBoth technicians.
, When the air dryer is in the charge cycle, what occurs? - Correct AnswersAir passes
through the compressors discharge valve, across the dryer's turbo cut-off piston, and to
the dryer's oil separator and desiccant. Finally, it exits the dryer through the delivery port to
the wet tank.
What is the typical pressure in which the low air pressure switch closes? - Correct
Answers60 PSI.
Technician A states that a low pressure warning switch will only illuminate a light on the
dash. Technician B states that a low pressure warning switch will only actuate a buzzer on
the dash. Who is correct? - Correct AnswersNeither. Most low pressure switches will
activate a warning light AND a buzzer.
Cut-in governor pressure is __ PSI below the cut-in pressure. - Correct Answers25.
Operating pressure (system pressure), in a properly functioning system, should vary
between governor __________ and _______? - Correct AnswersCut-in, and Cut-out.
One-way check valves are typically installed on the inlet ports of air reservoirs. T/F? -
Correct AnswersTrue.
Air brake systems contain the following subsystems: Air brake supply system, primary
circuit, secondary circuit, foundation brakes. T/F? - Correct AnswersTrue.
Technician A states the safety (pop off) valve is located on the wet tank. Technician B
states that the pop off valve is located only on the primary reservoir. Who is correct? -
Correct AnswersTechnician A only.
Air brake systems require a drain valve to remove moisture. How are they operated? -
Correct AnswersManually or automatically.
A safety valve is typically set at what pressure? - Correct Answers150 PSI.
Since 1977, on-highway trucks required a dual brake circuit (primary and secondary
circuit. This is referred to as FMVSS 121. T/F? - Correct AnswersTrue.
Solutions Assured Success
The governor can be integral or separate from the air compressor. T/F - Correct
AnswersTrue
Governor cut-out is adjustable, while cut-in can not be adjusted. T/F? - Correct
AnswersTrue.
Typical governor cut-out is approxamtely? - Correct Answers120-130 PSI.
What valve does the air compressor use to discharge the air to the air dryer? - Correct
AnswersDischarge valve.
Air compressors are commonly gear driven, but can be ________ driven in rare occasions.
- Correct AnswersBelt.
Air compressors can be cooled via _______ and/or ______ and are lubricated with
______? - Correct AnswersEngine coolant / Air / Engine Oil
Air dryers have two cycles. What are they? - Correct AnswersPurge and Charge.
What occurs during the purge cycle of an air dryer? - Correct AnswersWhen the governor
reaches cut-out pressure, the signal pressure from the governor's unloader valve operates
the purge valve on the dryer. This removes large contaminants, solid and liquid, from the
dryer.
During the purge cycle of an air dryer, governor cut-out is reached. Technician A states
that the cutoff piston in the dryer blocks the compressors supply air. Technician B states
that the dessicant in the dryer removes about 95% of the moisture in the air. Who's
correct? - Correct AnswersBoth technicians.
, When the air dryer is in the charge cycle, what occurs? - Correct AnswersAir passes
through the compressors discharge valve, across the dryer's turbo cut-off piston, and to
the dryer's oil separator and desiccant. Finally, it exits the dryer through the delivery port to
the wet tank.
What is the typical pressure in which the low air pressure switch closes? - Correct
Answers60 PSI.
Technician A states that a low pressure warning switch will only illuminate a light on the
dash. Technician B states that a low pressure warning switch will only actuate a buzzer on
the dash. Who is correct? - Correct AnswersNeither. Most low pressure switches will
activate a warning light AND a buzzer.
Cut-in governor pressure is __ PSI below the cut-in pressure. - Correct Answers25.
Operating pressure (system pressure), in a properly functioning system, should vary
between governor __________ and _______? - Correct AnswersCut-in, and Cut-out.
One-way check valves are typically installed on the inlet ports of air reservoirs. T/F? -
Correct AnswersTrue.
Air brake systems contain the following subsystems: Air brake supply system, primary
circuit, secondary circuit, foundation brakes. T/F? - Correct AnswersTrue.
Technician A states the safety (pop off) valve is located on the wet tank. Technician B
states that the pop off valve is located only on the primary reservoir. Who is correct? -
Correct AnswersTechnician A only.
Air brake systems require a drain valve to remove moisture. How are they operated? -
Correct AnswersManually or automatically.
A safety valve is typically set at what pressure? - Correct Answers150 PSI.
Since 1977, on-highway trucks required a dual brake circuit (primary and secondary
circuit. This is referred to as FMVSS 121. T/F? - Correct AnswersTrue.
