Question 1

Technician A says heater hoses from the water pump circulate water through the heat exchanger / heater core under the dash to warm the interior of the vehicle. Technician B says the coolant should always be filled to the hot fill line on the coolant reserve reservoir. Who is correct?

Accepted Answer

Technician A is correct. The heater hoses circulate hot water from the engine through the heater core to provide warmth inside the vehicle. Technician B is incorrect as the coolant level should be filled according to the manufacturer's recommended level, which may vary depending on whether the engine is hot or cold.

Question 2

Technician A says an inertia switch is used to stop the flow of fuel in the event of an accident to avoid the possibility of fire. Technician B says the EVAP is used to re-direct the evaporating gas vapors into the exhaust system. Who is correct?

Accepted Answer

Technician A is correct. An inertia switch is used to shut off the fuel pump in the event of a collision to reduce the risk of fire. Technician B is incorrect as the EVAP system is used to capture and store fuel vapors, rather than redirecting them into the exhaust system.

Question 3

Technician A says when doing a pressure check of the cooling system it should be pressurized to approximately 15 pounds over the normal operating pressure. Technician B says the cooling system should be pressurized and then the pressurizing pump should be left attached to ensure the pressure does not drop indicating a leak. Who is correct?

Accepted Answer

Technician B is correct. The cooling system should be pressurized to the manufacturer's recommended pressure, typically around 15 psi, but it varies depending on the vehicle. After pressurizing the system, the pump should be left attached for a period of time, usually around 15-20 minutes, to see if there is any drop in pressure. If the pressure drops, it indicates a leak in the system.

Question 4

Technician A says the supplemental restraint system includes the seat belts as well as all the air bags. Technician B says the supplemental restraint system is not designed to deploy until the vehicle is moving at a minimum speed. Who is correct?

Accepted Answer

Technician A is correct. The supplemental restraint system includes the seat belts as well as all the air bags. 
Technician B is correct. The supplemental restraint system is designed to deploy only during a collision, which generally occurs when the vehicle is moving at a certain speed, typically greater than 10-15 mph.

Question 5

Technician A says air conditioning systems utilize the laws of thermodynamics. Technician B says in an air conditioning system, the condenser releases the heat to the outside air. Who is correct?

Accepted Answer

Both technicians are correct. Air conditioning systems utilize the laws of thermodynamics, which involve the transfer of heat. In an air conditioning system, the condenser releases the heat to the outside air in order to cool down the refrigerant after it has absorbed heat from indoors.

Question 6

Technician A says the thermostat is incorporated into the cooling system to control the temperature in the vehicle cabin. Technician B says the ratio for coolant should be two parts water to one part coolant. Who is correct?

Accepted Answer

The thermostat controls the engine's operating temperature, not the cabin temperature. The typical coolant to water ratio is usually one part coolant to one part water, not two parts water to one part coolant.

Question 7

When coolant is added to the cooling system it should be a _____________mixture of water and coolant.

Accepted Answer

The answer of When coolant is added to the cooling...

Question 8

The manual transmission is shifted by the operator to accelerate and to decelerate.

Accepted Answer

The manual transmission requires the operator to shift gears to control speed and acceleration.

Question 9

Technician A says the engine is usually mounted transversely on a front wheel drive vehicle. Technician B says the differential reverses the spinning energy from the engine from one direction to the opposite. Who is correct?

Accepted Answer

Technician A is correct because front-wheel-drive vehicles often have transversely mounted engines to save space and improve efficiency. Technician B is also correct because the differential changes the direction of power flow to allow the wheels to rotate in the opposite direction when necessary, such as when turning.

Question 10

Evaporation is best explained as gas becoming a liquid.

Accepted Answer

Evaporation is the process where liquid turns into a gas.

Question 11

The cooling system in most vehicles is a closed water system.

Accepted Answer

The cooling system in most vehicles consists of a closed loop where coolant (usually a mixture of water and antifreeze) is circulated through the engine to absorb heat and then through a radiator to release the heat into the air. This is a closed water system since the coolant continuously circulates within the system without being open to the environment.

Question 12

The water pump is either electrical or ____________________, in which case it is driven by a belt.

Accepted Answer

The answer of The water pump is either electrical or...

Question 13

Which of the following is not a part of the air conditioning system?

Accepted Answer

Thermostat is not a part of the air conditioning system. It is part of the heating system and is used to regulate the temperature of the indoor environment.

Question 14

Technician A says the fuel pump may be driven by the camshaft. Technician B says the fuel pump is usually replaced when damaged, as it is not a repairable part. Who is correct?

Accepted Answer

Both statements are correct. Some fuel pumps, especially mechanical ones, can indeed be driven by the camshaft. Additionally, fuel pumps are typically replaced rather than repaired when they fail, due to the complexity and precision required for their operation.

Question 15

The _______________ joint is at the wheel end of the drive shaft on a front wheel drive system.

Accepted Answer

The answer of The _______________ joint is at the wheel...

Question 16

Technician A says dual air bags are required on all late model cars. Technician B says side curtain air bags deploy only during an imminent rollover. Who is correct?

Accepted Answer

The answer of Technician A says dual air bags are...

Question 17

Fuel pumps are either mechanical or ______________________.

Accepted Answer

The answer of Fuel pumps are either mechanical or ______________________....

Question 18

Noise, vibration and harshness is often abbreviated as ___________.

Accepted Answer

The answer of Noise, vibration and harshness is often abbreviated...

Question 19

The radiator in an automobile serves as a heat exchanger.

Accepted Answer

The purpose of the radiator in an automobile is to transfer heat from the engine coolant to the outside air, making it a heat exchanger.

Question 20

The compressor pressurizes the liquid refrigerant in an air conditioning system causing it to vaporize.

Accepted Answer

The compressor pressurizes the refrigerant, but it is in its gaseous state when it enters the compressor. The process of pressurization increases its temperature, but the refrigerant is already a vapor before compression.

Quiz 36: Mechanical Systems