Is it the threads? I have used teflon tape in the past. The recovery tank shouldnt get full enough to leak out the cap though unless your radiator cap is bad.
I am dealing with 27 year old plastic that has become brittle.I don't mind a good used tank or a universal tank.Just need something functional that's why I asked if it would work. I figured somebody possibly went that route.
I actually had the same problem as you, I used the 2.5 universal tank made by inderdynamics. The kit is a royal pain to install and the tubing provided is garbage, as the tank leaks a little around the petcock area. I even used hose clamps that I bought separately but it still leaks.
Junkyard tank would be a good one too. The three I have had havent been brittle, but I suppose it could be that dry Texas air. A wanted ad in the mall should get you some, maybe from a northern state.