C15 oil tank and feed pipes

[andrewkind]

I am slowly restoring a 1967 C15G. I had to replace the oil tank. The new tank has the feed, return and banjo pipes but there is also an inlet or outlet pipe at the top of the tank. I can not work out where this joins the system. Is it just a breather?

[SIE7RA]

yes it is a breather,i have attached a pipe to it,and directed it on to rear chain

[andrewkind]

Many thanks. That saved a lot of head scratching.