Fill the oil reservoir with proper oil (Air Tool oil or 10W grade equivalent for 9 lb.and 15 lb.class and Rock Drill oil for the 38 lb.and 60 lb.class.) Check all nuts and bolts to ensure they are tight on the tool. Make sure retainer locks in place. Replace retainer and or springs if worn.
[pdf] Rotor clearance issues or debris can lead to metallic contact sounds Loose or worn belts squeal or howl, especially under load Airflow pulsations, valve leaks, or turbulence create hissing or whistling Bolts, nuts, and mounting pads loosen over time, amplifying noise
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