EVT Hydraulic Systems & Aerial Apparatus Flashcards

When inspecting aerial apparatus outriggers, what must be verified before extending the aerial device?

Answer: Outriggers are fully deployed and pads on solid ground

Outriggers must be fully deployed and support pads placed on solid, level ground to provide the required stability before aerial operations.

Which hydraulic fluid property is most critical for proper operation of aerial apparatus in cold climates?

Answer: Viscosity index

Viscosity index indicates how much a fluid's viscosity changes with temperature, which is critical for consistent performance in cold climates.

What is the correct procedure when aerial apparatus hydraulic fluid appears milky or foamy?

Answer: Change fluid and inspect for water contamination source

Milky or foamy hydraulic fluid indicates water contamination, requiring immediate fluid replacement and identification of the water source.

During an aerial ladder annual service test, how long must the aerial withstand the rated load test without retraction or lowering?

Answer: 5 minutes

NFPA 1901 requires aerial devices to hold the rated load at the worst-case position for 5 minutes without measurable drift or lowering.

What type of hydraulic fitting is preferred for aerial apparatus high-pressure lines due to its leak-free performance?

Answer: SAE O-ring face seal (ORFS)

SAE O-ring face seal (ORFS) fittings are preferred for high-pressure hydraulic lines because the O-ring provides a reliable, leak-free metal-to-metal seal.

What is the recommended method for bleeding air from an aerial apparatus hydraulic system after a component replacement?

Answer: Cycle the hydraulic actuators slowly through full range multiple times

Slowly cycling hydraulic actuators through their full range of motion multiple times forces air bubbles to migrate back to the reservoir where they can escape.