Repair of an internal combustion rock drill that is not turning

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]