During a demolition project, an operator is using an hydraulic breaker attachment. After several hours of operation, they notice a significant decrease in impact force, even though the engine RPM remains constant. What is the most probable cause of this issue?

Question: During a demolition project, an operator is using an hydraulic breaker attachment. After several hours of operation, they notice a significant decrease in impact force, even though the engine RPM remains constant. What is the most probable cause of this issue?

Answer options:

• An overfilled hydraulic reservoir. ✅ Worn hammer seals or nitrogen accumulator pressure loss in the breaker.
• A plugged fuel filter.
• The boom relief valve is stuck open.

Correct answer: Worn hammer seals or nitrogen accumulator pressure loss in the breaker.

Explanation: A decrease in the impact force of a hydraulic breaker, while engine RPM is stable, most commonly indicates an issue with the breaker itself. Worn hammer seals can lead to internal hydraulic bypass, reducing impact, and loss of nitrogen pressure in the accumulator directly reduces the stored energy for impacting. A plugged fuel filter would affect engine performance, an overfilled reservoir causes other issues, and a stuck-open boom relief valve would primarily affect boom movement.