MEOC Hydraulic Systems & Fluid Management 2

Question 1

What is the correct procedure for checking the hydraulic fluid level on a mini excavator?

Accepted Answer

Check on level ground with the machine in the manufacturer-specified parked position and the engine off

Answer

Check immediately after operation while components are still hot and pressurized

Answer

Check only while the engine is running at full throttle

Answer

Check with the boom fully extended and bucket raised overhead

Question 2

What is the most common cause of hydraulic fluid overheating in a mini excavator?

Accepted Answer

Continuous heavy loading, restricted fluid flow, or a blocked oil cooler

Answer

Using ISO VG 68 fluid when ISO VG 46 is specified

Answer

Operating the machine in ambient temperatures below 32°F

Answer

Running the engine at low RPM during light-duty tasks

Question 3

What is the primary risk of mixing incompatible hydraulic fluid brands or types in an emergency?

Accepted Answer

Incompatible additive packages may degrade fluid performance and damage seals or internal components

Answer

The mixed fluid will immediately seize the hydraulic pump

Answer

The fluid viscosity will become too thick to flow through the system

Answer

Engine RPM will automatically increase to compensate for reduced flow

Question 4

What does milky or cloudy hydraulic fluid indicate in a mini excavator?

Accepted Answer

Water contamination has entered and emulsified with the hydraulic fluid

Answer

The fluid has an exceptionally high additive concentration and is performing optimally

Answer

The fluid viscosity is appropriate for current cold-weather operating conditions

Answer

The fluid has reached the end of its normal service life with no harmful effects

Question 5

What is the function of a hydraulic accumulator found on some mini excavators?

Accepted Answer

To store pressurized fluid for pilot control, pressure spike dampening, or brief high-demand functions

Answer

To increase the maximum output pressure of the hydraulic pump

Answer

To filter fine contaminants from the hydraulic fluid circuit

Answer

To convert hydraulic pressure into electrical signals for the control system

Question 6

How should hydraulic hoses be inspected before operating a mini excavator?

Accepted Answer

Visually check the entire hose length for cracks, abrasion, bulging, leaks, and verify fittings are secure

Answer

Inspection is only required if the machine has been idle for more than 30 days

Answer

Bend each hose sharply to test for internal stiffness and brittleness

Answer

Inspect only the hose-to-cylinder connection points; mid-hose failures are rare

Question 7

What is the correct response to a high-pressure hydraulic fluid injection injury on a job site?

Accepted Answer

Seek immediate emergency medical attention — this is a life-threatening injury even if the wound looks minor

Answer

Wash the area with water and soap, bandage it, and return to work if pain subsides

Answer

Apply a tourniquet above the injection site and wait for symptoms to worsen before acting

Answer

Apply topical antibiotic ointment and monitor the site for 24 hours