Leaking Bolt on Water Pump

All,

I just swapped out my Power Steering Pump as it was leaking fluid. The swap seemed to go fine, and it's driving well, but I noticed that when I loosened this bolt, to release tension on the belt....coolan fluid runs out. When I removed it completely, it gushed like a hose. And after the swap I tightened it up as much as I could....but now it's now slowly leaking.

I pulled it all the way out and it seems like a bolt with a long smooth shoulder on it.

How does this thing seal, and will it damage ( or help ) anything if I put some sealant on it ?

Thanks.....