EETC - Equipment & Engine Training Council Driveline and Hydraulic Systems Questions and Answers

Question 1

A technician is troubleshooting a zero-turn mower with a hydrostatic transaxle that is noisy and has a lack of power after a short period of operation.
The fluid level is correct.
Which of the following is the MOST likely first step in the diagnostic process?

Accepted Answer

Purge the air from the hydrostatic system.

Answer

Check the condition of the drive belt and tensioner.

Answer

Disassemble the hydraulic pump for internal inspection.

Answer

Perform a hydraulic pressure test at the pump outlet.

Question 2

In a hydraulic system, what is the primary function of a relief valve?

Accepted Answer

To limit the maximum pressure within the system.

Answer

To filter contaminants from the hydraulic fluid.

Answer

To regulate the speed of hydraulic motors.

Answer

To cool the hydraulic fluid as it returns to the reservoir.

Question 3

A powershift transmission in a piece of utility equipment is exhibiting delayed, rough shifting and a noticeable shudder upon acceleration. Which of the following is the MOST likely cause of these symptoms?

Accepted Answer

A failing clutch pack or contaminated clutch surfaces.

Answer

Low hydraulic fluid temperature.

Answer

An incorrectly adjusted shift linkage.

Answer

A clogged transmission fluid filter.

Question 4

Which type of hydraulic pump is generally more tolerant of contamination, has a simpler design, and is typically lower in cost, but is only available as a fixed displacement unit?

Accepted Answer

Gear pump

Answer

Vane pump

Answer

Axial piston pump

Answer

Radial piston pump

Question 5

A technician hears a high-pitched whining or a sound like marbles rattling inside a hydraulic pump. The suction line filter is found to be severely clogged. This noise is most likely caused by:

Accepted Answer

Cavitation

Answer

Aeration

Answer

Detonation

Answer

Vibration

Question 6

In a final drive that uses a planetary gear set, what is the primary purpose of this arrangement?

Accepted Answer

To provide significant torque multiplication and speed reduction.

Answer

To increase the output speed while decreasing torque.

Answer

To allow for quick changes in the direction of rotation.

Answer

To act as a hydraulic clutch between the motor and the axle.