Preformed ac tune up on 5 year old Carrier condenser. During the tune up I came across a few points of concerns that need to be addressed. 3 ton Carrier- 1. System was low on R410a refrigerant, there is a leak present in the refrigeration cycle. 2. Compressor savor kit is weak and no longer reducing start up amps for system. 3. Filter was not fitted correctly in the return vent. This is the wrong spot the filter is in. Filter should be slid into bottom of furnace cabinet. 4. Leak should be injected into system to locate leak.