Deck 17: Truck Trailer Refrigeration Maintenance Procedures

Question 1

Air filters should be replaced at regular intervals or when a restriction indicator shows that the air filter is restricted. Performing this task will prevent:

A) A loss in horsepower.
B) Increased fuel consumption.
C) Shortened engine life.
D) All of the above can be prevented with proper air filter servicing.

Answer 1

D

Question 2

Which of the following should not be done when changing the engine fuel filters?

A) Tighten the secondary fuel filter until the rubber gasket makes contact with the filter base; then tighten and additional half turn.
B) Install the primary fuel filter and spin it on, leaving the filter loose.
C) Fill both the primary and secondary filter with fuel before installation.
D) Operate the manual hand pump located on the injection pump until fuel bubbles surround the top of the primary filter.

Answer 2

C

Question 3

What should be done before draining the engine oil of a refrigeration unit?

A) Warm the engine to operating temperature
B) Ensure you have a drain pan capable of containing all the engine oil
C) Check the engine hour meter to make sure the unit has the required hours
D) All of the above should be performed before draining the engine oil

Answer 3

D

Question 4

A compressor pump down is performed in order to change the compressor oil. With the unit operating in high speed cool:

A) Front seat the receiver tank outlet valve
B) Front seat the suction service valve
C) Front seat the discharge service valve
D) Front seat the bypass check valve

Question 5

What is the recommended ratio of ethylene glycol based coolant and water for the engine cooling system?

A) 30/70
B) 40/60
C) 50/50
D) 60/40

Question 6

When removing the manifold gauge set with the engine running never:

A) Back seat the discharge service valve
B) Front seat the discharge service valve
C) Open both manifold gauges to bleed refrigerant from the discharge gauge hose into the compressor suction side
D) Back seat the suction service valve

Question 7

When manually recharging a refrigeration system start by performing a proper evacuation and then weigh in the correct amount of refrigerant by:

A) Dispensing vaporous refrigerant into the discharge side of the system
B) Dispensing vaporous refrigerant into the suction side of the system
C) Dispensing liquid refrigerant into the discharge side of the system
D) Dispensing liquid refrigerant into the suction side of the system

Question 8

Before installing a manifold gauge set on a refrigeration unit make sure:

A) The service valves are back seated
B) The service valves are mid seated
C) The service valves are mid seated turn clockwise
D) The service valves are front seated

Question 9

Which of the following in not a recommended way to test engine glow plugs?

A) Test amperage of entire glow plug circuit and compare to manufactures specifications.
B) Individually check the resistance of each glow plug and compare to manufactures specifications.
C) Check the voltage delivered to each glow plug and compare to manufactures specifications.
D) Test the amperage of each glow plug individually and compare to manufactures specifications.

Question 10

How often should the refrigeration units cooling system be flushed and replaced?

A) Every year
B) Every 2 years
C) Every 3 years
D) Every 4 years

Question 11

The defrost air switch initiates a defrost cycle buy comparing:

A) The differential air pressure on either side of the condenser fan.
B) The difference in air pressure between the condenser inlet and evaporator outlet.
C) The difference in air pressure between the condenser outlet and evaporator inlet.
D) The differential air pressure in either side of the evaporator coil.

Question 12

What procedure would be used to repair the internal valve of SV2 on a solenoid control system (Carrier)?

A) A compressor pump down
B) A low side pump down
C) A evacuation procedure
D) A refrigerant removal

Question 13

Why is it recommended to evacuate from three points on a solenoid control system (Carrier)?

A) Because the system is larger
B) Because of the discharge check valve
C) Because of the closed SV2 solenoid valve
D) Because of the closed pilot solenoid valve

Question 14

What component initiates the end of the defrost cycle?

A) The defrost air switch.
B) The air restriction indicator.
C) The thermostat.
D) The defrost termination switch.

Question 15

In order to perform refrigerant maintenance on the low side of the refrigeration system you will need to perform a low side pump down. With the unit running in high speed cool:

A) Front seat the receiver tank outlet valve
B) Front seat the suction service valve
C) Front seat the discharge service valve
D) Front seat the bypass check valve