Club ac cleaning mini split unit, took apart wall unit and vacuumed and brushed dirt out of coils, brushed and vacuumed blower wheel, filters cleaned by customer, cleaned exterior of unit with rag and water. Customer noticed a odd hissing sound coming from unit, I also noticed and he would like to get a service tech to come out, possibly same issue happened last year. Unit doesn't feel like it's cooling as it should be but when I put thermometer to it on 65 it reads 65-67 coming out unit. No other issues Outdoor unit, cleaned coils with brush, cleaned exterior with rag and wd40, no issues.