DTC DTC Hydraulic Systems and Accessories

Question 1

What is the primary function of a hydraulic pump on a diesel-powered work truck or equipment?

Accepted Answer

To convert mechanical energy from the engine into hydraulic pressure to power accessories

Answer

To cool the engine coolant circuit

Answer

To pressurize the fuel injection system

Answer

To regulate turbocharger boost pressure

Question 2

Which type of hydraulic pump is most commonly used in heavy-duty diesel truck-mounted hydraulic systems?

Accepted Answer

Gear pump

Answer

Centrifugal pump

Answer

Diaphragm pump

Answer

Peristaltic pump

Question 3

What does 'cavitation' mean in the context of a diesel truck's hydraulic system?

Accepted Answer

Formation and collapse of vapor bubbles in the pump due to insufficient inlet pressure

Answer

Excessive back pressure in the return line

Answer

Air in the hydraulic cylinder causing spongy operation

Answer

Hydraulic fluid overheating due to high load cycles

Question 4

What is the role of the hydraulic system's relief valve?

Accepted Answer

To limit maximum system pressure and protect components from over-pressurization

Answer

To increase system pressure when loads are heavy

Answer

To direct flow to different actuators

Answer

To filter contaminants from the hydraulic fluid

Question 5

Which hydraulic fluid property is most critical to maintain for proper diesel truck hydraulic system performance in cold US winters?

Accepted Answer

Viscosity index

Answer

Flash point

Answer

Pour point

Answer

Acid number

Question 6

What symptom indicates air contamination in a diesel truck's hydraulic system?

Accepted Answer

Foamy fluid in the reservoir and spongy or erratic actuator movement

Answer

High system pressure at idle

Answer

Increased hydraulic pump speed

Answer

Dark brown fluid with a burnt odor