What oil to use for door closer?

[Hello Ruan]

Hey everyone,

So a non cycling related question here. I have a Ryobi 8803 door closer but while I was adjusting it I turned one screw too far and the oil came out. Can anyone please help me and tell me which oil I must buy to replace all of the oil that I have now lost.

Thanks a lot and happy new year!
 

[David Marshall]

Haven't a clue what they use but I would just top it up with fork oil.  I have reconditioned my press and jack with it before.  Doubt that the oil weight would be important in this application so get the cheapest.