I just picked up a complete AC system (compressor, condenser, hoses everything need). I also ordered new o rings for all connections. But my question is the ac has been removed for 4 years and the ports on the firewall is open. Do I need to take the whole thing put from underneath the dashboard and flush it clean?? or I can do it without removing it?? the compressor still works but it traps a lot of dirts inside from sitting in the junk yard for a good period. anyway to clean it up?? same as the hoses, what's the best way to flush em up?