This is pretty common for Perkins and CAV Pumps. They are nice in that they have very little moving parts, and are probably one of the easiest pumps that I know of to rebuild, but they have a lot of sealing surfaces to get that.
You can get rebuild kits for the CAV pumps readily, and not for much money if you chose to rebuild it yourself.
If you got 45 minutes, there is a guy that rebuilt a CAV pump for a 4.108 diesel Engine, and showed how it was done from start to finish. If I was you, I would watch that, and make a determination if you want to tackle the problem or not. A 45 minute youtube video might save you a lot of money on having it done in a shop.
It is your call, but 45 minutes doing something for free (watching youtube), would be worth it to me.