Came out to call to do a leak search, vacuum the system, and recharge the unit. System was running low on refrigerant when I came out last. After double checking it, I also found the washable filters to be severely dirty, causing an air restriction across the evaporator coil. Customer and I agreed on pricing before work was done. I took out old refrigerant. Put nitrogen in the system and checked for leaks. Found a minor one on gasket out at the condenser. Emptied the system of nitrogen and pulled an extensive vacuum on system. Was able to pull a good vacuum with no signs of any other leaks. Charged system with 43 oz’s of 410a, as recommended on nameplate. Cycled system on and checked operation in heating and in cooling. Had no problems with either mode. Advised customer to have unit replaced if any other issues arise, do to the amount of problems it has had and the amount of money it has cost him.