An operator is repeatedly experiencing the quick-coupler releasing the attachment inadvertently when performing aggressive digging with a heavy bucket. The quick-coupler system is hydraulic. What is a critical check the operator or technician should perform if the mechanical locking pins appear to be fully extended and engaged?

Question: An operator is repeatedly experiencing the quick-coupler releasing the attachment inadvertently when performing aggressive digging with a heavy bucket. The quick-coupler system is hydraulic. What is a critical check the operator or technician should perform if the mechanical locking pins appear to be fully extended and engaged?

Answer options: ✅ Verify the quick-coupler's hydraulic pressure relief valve setting.

• Check the engine's exhaust system for leaks.
• Inspect the cab's HVAC filter for blockage.
• Measure the tire pressure on the front axle.

Correct answer: Verify the quick-coupler's hydraulic pressure relief valve setting.

Explanation: If mechanical locking pins appear engaged but the coupler is releasing under load, there might be an issue with the hydraulic pressure maintaining the lock. Verifying the quick-coupler's hydraulic pressure relief valve setting is crucial, as an incorrect setting could allow pressure to bleed off, leading to accidental release. The other options are unrelated to the quick-coupler's locking mechanism.