HEAVY DUTY MECHANIC EXAM
(V)QUESTIONS & ANSWERS(RATED
A+)
A trailer with electric brakes is being diagnosed for poor brake application when
loaded. The technician has set the gain on the controller correctly and confirmed that
power is available at the trailers wheels. How should the technician proceed to
determine the fault?
a) Check the polarity of the magnets with a compass to verify operation of each
wheel
b) Monitor the brake controller voltage and replace the magnets at each wheel
c) Check resistance of the magnets and compare them to each other
d) Measure the current flow in the brake circuit to each wheel to verify the
connections are secure - ANSWERD)
The 180 foot pounds of torque are input at a transfer case input shaft. In low range
(1.8:1 ratio), how much torque is delivered to the drive pinion of the front axle of a
four wheel drive vehicle?
a) 162 pounds
b) 150 pounds
c) 125 pounds
d) 178 pounds - ANSWERA)
What is the problem in a manual transmission that is noisy under load in all reduction
gears?
a) Clutch shaft pilot bearing is worn
b) Cluster shaft bearings damaged
c) First speed output gear teeth chipped
d) Speedometer drive gear chipped - ANSWERB)
How must you repair a Weather Pack connector?
a) Remove the secondary lock then pull the terminal out of the cavity
b) Remove the primary lock then locate the entry canal and release the terminal with
the appropriate tool
c) Remove the primary lock then remove the secondary lock
d) Remove the seal then locate the entry canal and release the terminal with the
appropriate tool - ANSWERB)
What engine operating condition must be met before a bidirectional scan tool can
perform a cylinder balance test and what does the scanner actually do?
a) Engine at operating temperature; turns off individual ignition coils
b) Engine at cold start temperature; turns off individual injectors
c) Engine at cold start temperature; turns off individual ignition coils
d) Engine at operating temperature; turns off individual injectors - ANSWERD)
,What two things should be observed when testing fuel control system response by
creating a vacuum leak?
a) Voltage rise in O2 sensor output and a decrease in injector dwell
b) Decrease in RPM and an advance in spark timing
c) Voltage drop in O2 sensor output and an increase in injector dwell
d) Increase in RPM and a drop in spark advance - ANSWERC)
There is a loss of coolant. Coolant was recently added to a hot engine. There is a
white smoke from the exhaust when the engine is loaded. During a cooling system
pressure test, the pressure drops slowly but no external leaks are seen. What is the
problem?
a) Cylinder head gasket is leaking, pressurizing the cooling system
b) Transmission cooler is leaking coolant into the transmission
c) Cylinder head has cracked and is leaking coolant into the combustion chamber
d) Intake manifold is leaking into the crankcase - ANSWERC)
What is the correct procedure for preparing an engine hoist to lift an engine?
a) Adjust the engine hoist to carry the engine as low as possible, and lift the engine
b) Push the legs on the hoist in, and extend the lift arm to access the engine
c) Adjust the leg length and then adjust the lift beam length to lift the engine
d) Extend the legs as far as possible, then pull the lifting arm in for stability -
ANSWERC)
A vehicle equipped with an automatic transaxle is not shifting correctly. The first
diagnostic step would be to?
a) Perform a hydraulic pressure test
b) Inspect and adjust all linkages
c) Check the fluid level and type
d) Adjust all the bands to specification - ANSWERC)
Which adjustment procedures are in the correct sequence for adjusting a removable
carrier rear-axle final drive assembly?
a) Side bearing preload, then clutch breakaway torque
b) Backlash, then pinion gear clearance
c) Differential pinion clearance, then side bearing preload
d) Pinion bearing preload, and pinion depth - ANSWERD)
When repairing automatic transmissions, which statement is true?
a) Cooler lines must be flushed before the transmission is installed
b) Clutch pack clearances must be measured before replacement
c) Cooler lines must be flushed before the transmission is removed
d) Clutch pack plates are lubricated with vaseline before installing - ANSWERA)
Which is correct for boost charging a dead battery?
a) Negative cable should be connected to the dead battery first
b) Positive cable should be connected to the charged battery first
c) Positive cable should be connected to the charged battery last
d) Negative cable should be connected to the charged battery last - ANSWERB)
What precautions must be followed when installing an instrument cluster?
, a) Install a static strap then remove cluster from the anti-static bag
b) Replace all fasteners and torque them to specification
c) Remove the lens on the gauge cluster then coat it with anti-static spray
d) Reset the odometer then record it on the work order - ANSWERA)
This is true when repairing or servicing an air conditioning system?
a) The labels attached to A/C systems always indicate the correct refrigerant in the
system
b) Refrigerant recovery of A/C systems is used to reduce customer costs
c) A/C systems are recharged by adding refrigerant according to discharge
temperature
d) A/C systems are evacuated to remove moisture and air from the system -
ANSWERD)
When a tire has a vibration at 40 to 60 kilometers per hour, a suspension bounce
test is performed, the car bounces 5 or 6 times before coming to rest. What is the
cause?
a) Weak shock absorbers
b) Weak or broken spring
c) Dynamic imbalance in the tires
d) Cracked shock mount - ANSWERA)
When a loaded ball joint has 0.130" (3.30 mm) vertical movement, how would you
correct this problem?
a) Grease the joint, then retest
b) Test drive for unpredictable steering, then examine the wear indicator
c) Replace the joint, and perform a wheel alignment
d) Joint movement is acceptable then check the wheel alignment - ANSWERC)
What must be done in order to ensure the cylinder functions correctly when replacing
a master cylinder?
a) Bench bleed the master cylinder, then install and fill the reservoir
b) Install the master cylinder, and adjust the brakes
c) Install the master cylinder, bleed the quick take up valve, then fill the reservoir
d) Transfer the proportioning valves, and install the master cylinder - ANSWERA)
What must you do when a vehicle is displaying both an illuminated air bag light and
MIL light?
a) Clear all the trouble codes first
b) Diagnose the air bag light first
c) Disconnect the battery
d) Diagnose the check engine light first - ANSWERB)
What precautions must be taken when replacing the coil assembly found in a
Supplemental Inflatable Restraint steering column?
a) Lock the steering column, and disable the airbag
b) Remove the airbag module, then the signal light switch
c) Lock the steering column, and remove the steering wheel
d) Remove the steering wheel, and disable the airbag - ANSWERA)
(V)QUESTIONS & ANSWERS(RATED
A+)
A trailer with electric brakes is being diagnosed for poor brake application when
loaded. The technician has set the gain on the controller correctly and confirmed that
power is available at the trailers wheels. How should the technician proceed to
determine the fault?
a) Check the polarity of the magnets with a compass to verify operation of each
wheel
b) Monitor the brake controller voltage and replace the magnets at each wheel
c) Check resistance of the magnets and compare them to each other
d) Measure the current flow in the brake circuit to each wheel to verify the
connections are secure - ANSWERD)
The 180 foot pounds of torque are input at a transfer case input shaft. In low range
(1.8:1 ratio), how much torque is delivered to the drive pinion of the front axle of a
four wheel drive vehicle?
a) 162 pounds
b) 150 pounds
c) 125 pounds
d) 178 pounds - ANSWERA)
What is the problem in a manual transmission that is noisy under load in all reduction
gears?
a) Clutch shaft pilot bearing is worn
b) Cluster shaft bearings damaged
c) First speed output gear teeth chipped
d) Speedometer drive gear chipped - ANSWERB)
How must you repair a Weather Pack connector?
a) Remove the secondary lock then pull the terminal out of the cavity
b) Remove the primary lock then locate the entry canal and release the terminal with
the appropriate tool
c) Remove the primary lock then remove the secondary lock
d) Remove the seal then locate the entry canal and release the terminal with the
appropriate tool - ANSWERB)
What engine operating condition must be met before a bidirectional scan tool can
perform a cylinder balance test and what does the scanner actually do?
a) Engine at operating temperature; turns off individual ignition coils
b) Engine at cold start temperature; turns off individual injectors
c) Engine at cold start temperature; turns off individual ignition coils
d) Engine at operating temperature; turns off individual injectors - ANSWERD)
,What two things should be observed when testing fuel control system response by
creating a vacuum leak?
a) Voltage rise in O2 sensor output and a decrease in injector dwell
b) Decrease in RPM and an advance in spark timing
c) Voltage drop in O2 sensor output and an increase in injector dwell
d) Increase in RPM and a drop in spark advance - ANSWERC)
There is a loss of coolant. Coolant was recently added to a hot engine. There is a
white smoke from the exhaust when the engine is loaded. During a cooling system
pressure test, the pressure drops slowly but no external leaks are seen. What is the
problem?
a) Cylinder head gasket is leaking, pressurizing the cooling system
b) Transmission cooler is leaking coolant into the transmission
c) Cylinder head has cracked and is leaking coolant into the combustion chamber
d) Intake manifold is leaking into the crankcase - ANSWERC)
What is the correct procedure for preparing an engine hoist to lift an engine?
a) Adjust the engine hoist to carry the engine as low as possible, and lift the engine
b) Push the legs on the hoist in, and extend the lift arm to access the engine
c) Adjust the leg length and then adjust the lift beam length to lift the engine
d) Extend the legs as far as possible, then pull the lifting arm in for stability -
ANSWERC)
A vehicle equipped with an automatic transaxle is not shifting correctly. The first
diagnostic step would be to?
a) Perform a hydraulic pressure test
b) Inspect and adjust all linkages
c) Check the fluid level and type
d) Adjust all the bands to specification - ANSWERC)
Which adjustment procedures are in the correct sequence for adjusting a removable
carrier rear-axle final drive assembly?
a) Side bearing preload, then clutch breakaway torque
b) Backlash, then pinion gear clearance
c) Differential pinion clearance, then side bearing preload
d) Pinion bearing preload, and pinion depth - ANSWERD)
When repairing automatic transmissions, which statement is true?
a) Cooler lines must be flushed before the transmission is installed
b) Clutch pack clearances must be measured before replacement
c) Cooler lines must be flushed before the transmission is removed
d) Clutch pack plates are lubricated with vaseline before installing - ANSWERA)
Which is correct for boost charging a dead battery?
a) Negative cable should be connected to the dead battery first
b) Positive cable should be connected to the charged battery first
c) Positive cable should be connected to the charged battery last
d) Negative cable should be connected to the charged battery last - ANSWERB)
What precautions must be followed when installing an instrument cluster?
, a) Install a static strap then remove cluster from the anti-static bag
b) Replace all fasteners and torque them to specification
c) Remove the lens on the gauge cluster then coat it with anti-static spray
d) Reset the odometer then record it on the work order - ANSWERA)
This is true when repairing or servicing an air conditioning system?
a) The labels attached to A/C systems always indicate the correct refrigerant in the
system
b) Refrigerant recovery of A/C systems is used to reduce customer costs
c) A/C systems are recharged by adding refrigerant according to discharge
temperature
d) A/C systems are evacuated to remove moisture and air from the system -
ANSWERD)
When a tire has a vibration at 40 to 60 kilometers per hour, a suspension bounce
test is performed, the car bounces 5 or 6 times before coming to rest. What is the
cause?
a) Weak shock absorbers
b) Weak or broken spring
c) Dynamic imbalance in the tires
d) Cracked shock mount - ANSWERA)
When a loaded ball joint has 0.130" (3.30 mm) vertical movement, how would you
correct this problem?
a) Grease the joint, then retest
b) Test drive for unpredictable steering, then examine the wear indicator
c) Replace the joint, and perform a wheel alignment
d) Joint movement is acceptable then check the wheel alignment - ANSWERC)
What must be done in order to ensure the cylinder functions correctly when replacing
a master cylinder?
a) Bench bleed the master cylinder, then install and fill the reservoir
b) Install the master cylinder, and adjust the brakes
c) Install the master cylinder, bleed the quick take up valve, then fill the reservoir
d) Transfer the proportioning valves, and install the master cylinder - ANSWERA)
What must you do when a vehicle is displaying both an illuminated air bag light and
MIL light?
a) Clear all the trouble codes first
b) Diagnose the air bag light first
c) Disconnect the battery
d) Diagnose the check engine light first - ANSWERB)
What precautions must be taken when replacing the coil assembly found in a
Supplemental Inflatable Restraint steering column?
a) Lock the steering column, and disable the airbag
b) Remove the airbag module, then the signal light switch
c) Lock the steering column, and remove the steering wheel
d) Remove the steering wheel, and disable the airbag - ANSWERA)
