Where does it Go?

Coolant. I top off the resevoir but when I check it always seems empty. I think someone mentioned leaky intake man gasket. Some one else told me of a leak at the weephole on the water pump, but only while running. I don't have water in the oil and there is nothing on the ground and nothing in the exhaust. The van has 134K miles on it but runs pretty strong.
Thanks.

I had a leaking resevoir myself. Anything I put in there went directly to the ground.

In your case however, I would start by getting under the van and looking at the lower radiator hose. If a white deposit has formed from the top of the lower radiator hose down to where it turns to the radiator, I'd think the water pump is suspect at that point....

I had a similar experience, the coolant level in the resevoir going down. I found a small puncture in the lower radiator hose that only leaked under pressure, which meant it would leak when I was driving, but didn't leave a drop on my driveway.
Even when idling the van in the driveway, only a small drop weeped out of the puncture and dangled on the bottom of the hose.
I replaced the hose and later found another possibility, which was I didn't tighten one of the hose clamps enough, and it was pressure leaking the same way. A few turns of the screw driver took care of that.