I know there is a ton on this in the archives...but I still can't make complete sense of my options (rookie).  Despite asking the PO specifically if there were head gasket leaks (he said no), I believe I have a weepy head gasket.  After sealing up oil leaks and doing a coolant flush after I bought the van, I am consistently loosing coolant, though I don't see any drips.  Upon going through the PO's old records I found a folded up (didn't noticed this before I bought it) reciept that stated heads were leaking.  The mechanic at the time recommended a sealer of some sort.  That was in January of 04...apprx 17000 miles ago.  It is not overheating, or running poorly...just having to top off coolant every 3-400 miles.  What I am wondering is....what are my options.  Do I just wait until it starts leaking internally and take care of it then....or am I sitting on a time-bomb that I should address right away.   I  noticed some posts about the subaru conditioner.  Should I go that
 route or is it too late for such things.