Vacuum Problem on 300D 78

[muybweno]

hey guys....
got another problem. front passenger door wont lock at all, the lock will always stay up. I can force the lock to go down but it will pop back up with force. I tried to strace the vacuum lines from the vacuum pump to see if i have oil in the vacuum system because i was told that oil would complicate stuff. I did find a little bit of oil but it was located in one of the stop valves ( small blue cylinders branching off from the main vacuum hose that connects the the brake master cylinder). There are 2 of these valves, one of them are ok, but the other when i pull it out shows a little oil on the tip of the connector and also releases some vacuum from the system. when i removed the line from this stop valve, it seemed like air was coming out of it. I then tried to lock the doors and then the front passenger door lock when down.

do i need to replace this valve or is there something else that i need to check on. Also will i have any performance problems such as the A/C system malfunctioning...and ect..

your comments are greatly appreciated