1986 Vanagon, automatic transmission drips. on 1990 Volkswagen Vanagon

It seems to be coming from a weep hole in the case. It's less than a pint per week. What might cause it and what might it cost to fix?

1 answer 3 comments
I add a pint a week to keep it up to the middle of the stick indicator.
did you ck it running or off?
Running. Keeping the fluid level up is not the problem. The dripping fluid is.