CPO Hydraulic Systems & Controls Flashcards
6 cards from real CPO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CPO Hydraulic Systems & Controls flashcards as text
Why is it important to use the correct viscosity hydraulic oil for a concrete pump?
Answer: To ensure proper lubrication and system efficiency across operating temperatures
Correct viscosity ensures adequate lubrication, efficient power transfer, and prevents damage across the full range of operating temperatures.
How should an operator check for internal hydraulic cylinder leakage?
Answer: Observe for cylinder drift under load with control valves in neutral
Internal cylinder leakage is detected by placing the cylinder under load, putting controls in neutral, and observing for unintended drift or movement.
What indicates that a hydraulic filter element needs replacement?
Answer: Filter bypass indicator lamp activates or differential pressure increases
A filter bypass indicator or high differential pressure across the filter signals that the element is clogged and needs immediate replacement.
What is 'cavitation' in a hydraulic pump and what causes it?
Answer: Formation and collapse of vapor bubbles caused by insufficient fluid supply to the pump inlet
Cavitation occurs when the pump inlet is starved of fluid, causing vapor bubbles that collapse violently and erode pump components.
When is it safe to work near hydraulic lines that are under pressure?
Answer: Never — all work must be done only after the system is fully depressurized
No maintenance or repair work should ever be performed on hydraulic lines while under pressure, regardless of safety gear.
What maintenance action should be performed when replacing hydraulic fluid?
Answer: Flush the system and replace filters simultaneously
When changing hydraulic fluid, the system should be flushed and filters replaced at the same time to remove all degraded fluid and contaminants.