An operator is completing a task requiring precise material handling with a wheel loader. They notice that when trying to feather the controls, the hydraulic functions (lift and tilt) respond with an abrupt, jerky motion rather than a smooth, controlled movement. What could be a potential cause for this behaviour?

Question: An operator is completing a task requiring precise material handling with a wheel loader. They notice that when trying to feather the controls, the hydraulic functions (lift and tilt) respond with an abrupt, jerky motion rather than a smooth, controlled movement. What could be a potential cause for this behaviour?

Answer options: ✅ Air ingress into the hydraulic system causing cavitation.

• The hydraulic oil is excessively thick due to low operating temperature.
• A stuck main relief valve in the hydraulic pump.
• The return line filter is completely clogged.

Correct answer: Air ingress into the hydraulic system causing cavitation.

Explanation: Jerky, erratic hydraulic movements are a common symptom of air in the hydraulic system (cavitation). This causes compressible air bubbles to collapse violently, leading to inconsistent pressure and movement. Excessively thick oil (cold) would cause sluggish, not jerky movement. A stuck main relief valve would lead to constant low pressure or overheating, and a fully clogged return line filter would restrict flow and potentially trigger bypass, not directly cause jerky action.