CPO Hydraulic Systems & Controls Flashcards

What type of hydraulic fluid is most commonly specified for concrete pump systems?

Answer: Anti-wear hydraulic oil (AW-46)

AW-46 anti-wear hydraulic oil is the most common specification for concrete pump hydraulic systems due to its viscosity and additive package.

A sudden loss of boom movement during operation most likely indicates:

Answer: Hydraulic pump failure or loss of hydraulic pressure

Sudden loss of boom movement typically points to hydraulic pump failure, a burst hose, or a rapid pressure drop in the system.

What is the function of a hydraulic accumulator on a concrete pump?

Answer: To store and release hydraulic energy to dampen pressure spikes

A hydraulic accumulator stores pressurized fluid and releases it to smooth out pressure fluctuations and assist during peak demand.

What should an operator do immediately upon noticing a hydraulic hose leak under pressure?

Answer: Shut down the pump and depressurize the system before inspection

A pressurized hydraulic leak is extremely dangerous; the operator must immediately shut down and depressurize before any inspection.

Which hydraulic system component filters contaminants from the fluid?

Answer: Hydraulic filter/strainer

Hydraulic filters and strainers remove particulate contamination from the fluid, protecting pumps, valves, and cylinders from wear.

What does a directional control valve do in a concrete pump's hydraulic circuit?

Answer: Routes pressurized fluid to the correct actuator to control movement direction

Directional control valves direct hydraulic fluid to the appropriate cylinder or motor to produce the desired movement.