Mercedes: 1987 560sl mercedes, climate control system, port location

Question
i have to add freon or new refrigant to system
where do i add thank you 1987 560 sl mercedes

Answer
R107 560SL AC charge port location
http://www.mercedesshop.com/shopforum/showthread.php?p=1102785#post1102785

Climate Control System Died Suddenly                
"1988 560SEL"
http://www.mercedesshop.com/shopforum/showthread.php?p=819645#post819645

Can I always leave the A/C on?
http://www.mercedesshop.com/shopforum/showthread.php?p=601020#post601020

AC upgrades/improvements
http://www.mercedesshop.com/shopforum/showthread.php?p=618549#post618549