Question 1

Identify the INCORRECT statement in regards to the engine thermostat:&#10;A) The thermostat is fully open and closes as engine temperature increases.&#10;B) The thermostat is fully closed and opens as engine temperature increases.&#10;C) The thermostat must be open fully at a set number of degrees above the start to open temperature.&#10;D) The thermostat by-passes coolant to the water pump in the closed position.

Accepted Answer

The thermostat is designed to be fully closed when the engine is cold and opens as the engine temperature increases to allow coolant to flow through the radiator, not the other way around.

Question 2

In regards to pressure testing cooling systems and pressure caps identify the INCORRECT statement.&#10;A) The radiator cap when tested should not open until the system pressure indicated on the cap has been surpassed.&#10;B) Always build system pressure up 25% over the rated capacity when checking for cooling system leaks.&#10;C) When the cooling system has been allowed to cool down and radiator and heater hoses have been collapsed is an indication that the vacuum relief portion of the radiator cap may be defective.&#10;D) Never build system pressure more than 10% of the systems rated capacity when testing for coolant leaks.

Accepted Answer

Option B states to build system pressure 25% over the rated capacity, which is incorrect. The pressure should never exceed the system's rated capacity. The correct option should state to never exceed 10% of the system's rated capacity.

Question 3

Antifreeze performs three very important functions within the cooling system. Which of the following is not a function?&#10;A) Lowers the freezing point of the coolant&#10;B) Increases the boiling point of the coolant with an ant boiling agent&#10;C) Protects and lubricates the components of the cooling system&#10;D) Doubles the boiling point of the coolant mixture

Accepted Answer

Antifreeze increases the boiling point of the coolant with an anti-boiling agent, but it does not double the boiling point of the coolant mixture.

Question 4

Radiators should be checked on all vehicle services for:&#10;A) Condition of fins&#10;B) Cleanliness&#10;C) Mounting to vehicle&#10;D) All of the above should be checked

Accepted Answer

All the options mentioned above should be checked on all vehicle services for proper functioning of the radiator. Checking the condition of the fins ensures that they are not damaged or clogged and provide proper air flow for cooling. Checking cleanliness ensures that there is no dirt or debris blocking the radiator. Mounting to the vehicle needs to be checked to ensure that it is secure and the radiator is not loose, which could cause damage to it or other parts of the vehicle.

Question 5

Coolant filters should not be prematurely when they contain:&#10;A) A TDS (total dissolved solids) probe&#10;B) A SCA (supplemental coolant additive)&#10;C) Extended life coolant&#10;D) High silicate antifreeze

Accepted Answer

Coolant filters containing a Supplemental Coolant Additive (SCA) should not be changed prematurely because the SCA is designed to replenish protective chemicals in the coolant system over time. Removing the filter too early can lead to inadequate protection against corrosion and other coolant system issues.

Question 6

Which tool would most accurately measure the freeze protection of coolant?&#10;A) Hydrometer&#10;B) Refractometer&#10;C) Litmus tester&#10;D) Flow meter

Accepted Answer

A refractometer is the most accurate tool for measuring the freeze protection of coolant because it measures the refractive index of the coolant, which changes with its concentration and therefore its freezing point.

Question 7

A truck cooling system operates in a sequential order. Which of the following is the last in the chain of events?&#10;A) The fan hub is actuated.&#10;B) The shutterstat opens the shutters.&#10;C) The thermostat begins to open.&#10;D) The fanstat is triggered and sends a signal to lock up the fan hub.

Accepted Answer

The fan hub is actuated as the last step in the sequence, following the triggering of the fanstat and the opening of the shutters and thermostat.

Question 8

Which type of radiator construction allow designers to construct a vehicle with a lower hood?&#10;A) Counterflow&#10;B) Crossflow&#10;C) Downflow&#10;D) Sideflow

Accepted Answer

The answer of Which type of radiator construction allow designers...

Question 9

Engine cooling fan hubs may be:&#10;A) Actuated by an electrical signal or and air pressure signal as a means of engaging the clutch&#10;B) Of the viscous drive variety&#10;C) Controlled by a fanstat or engine management system&#10;D) All of the above statements are correct

Accepted Answer

All of the above statements are correct. Engine cooling fan hubs can be actuated by an electrical signal or air pressure signal to engage the clutch, they can be of the viscous drive variety, and they can be controlled by a fanstat or engine management system.

Question 10

Which of the following is not a type of radiator construction?&#10;A) Counterflow&#10;B) Crossflow&#10;C) Downflow&#10;D) Sideflow

Accepted Answer

Counterflow, crossflow, and downflow are all types of radiator construction that describe the direction of the coolant flow through the radiator. Sideflow, on the other hand, is not a recognized type of radiator construction.

Question 11

What causes coolant that was expelled from the system to the expansion tank to be return to the cooling system as the engine cools?&#10;A) Water pump flow valve&#10;B) Thermostat bypass circuit&#10;C) Vacuum relief valve in the pressure cap&#10;D) Pressure relief valve in the pressure cap

Accepted Answer

The answer of What causes coolant that was expelled from...

Question 12

If a vehicle is equipped with at winter front it:&#10;A) Must not cover more that 70% of the radiator surface&#10;B) Must not cover more than 75% of the radiator surface&#10;C) Must not cover more than 80% of the radiator surface&#10;D) Must not cover more than 85% of the radiator surface

Accepted Answer

The answer of If a vehicle is equipped with at...

Question 13

The heater core:&#10;A) Is located on the firewall of the truck.&#10;B) Has hot engine coolant circulated through it depending upon position of heater control valve.&#10;C) Is usually contained in an insulated case alongside the evaporator and blower motor.&#10;D) All of the above statements are correct

Accepted Answer

The answer of The heater core:&#10;A) Is located on the...

Question 14

If ethylene and propylene glycol-based coolants are mixed:&#10;A) It will cause and acidic reaction.&#10;B) The coolant will not stay mixed.&#10;C) The coolant additive package will need to be adjusted.&#10;D) Measuring the strength of the coolant is impossible.

Accepted Answer

The answer of If ethylene and propylene glycol-based coolants are...

Question 15

Identify the incorrect statement in regards to engine water pumps.&#10;A) The water pump is a positive displacement centrifugal pump.&#10;B) The water pump is a non-positive centrifugal pump.&#10;C) Coolant leaving the water pump flows first through the engine block and cylinder head and then into the radiator and back to the pump.&#10;D) Water pumps are either belt or gear driven.

Accepted Answer

The answer of Identify the incorrect statement in regards to...

Deck 8: Truck Engine Cooling Systems