AC cool check completed on three year-old horizontal Carrier system. Drain line has been flushed and treated. Condenser coils have been cleaned. I found that the outdoor torque booster was starting to fail. I presented repair options to the homeowner and they chose to have the repair completed today. I replaced the torque booster and function checked the system. All other mechanical and electrical components of the system are within manufacturer specs. No other major issues were found. The system is cooling properly at time of departure.