Diagnose mechanical problems and perform mechanical repairs and adjustments: PTO, hydraulics, emissions, air conditioning/heating, cab, instruments, brakes, frame, steering, suspension, tires, wheels, drive train, electrical system, fuel system (CNG & diesel) and other components which may need repair with assistance. Perform preventive maintenance inspections as specified, using mechanics hand tools and variety of shop equipment, which may include refrigeration, hydraulic jacks or hoist, welding tools, air pressure equipment, and other equipment as necessary.