Having just gone through this, I agree with the add some more coolant and see what happens. If it continues to disappear, go get a rebuild kit. The first time I drained the oil, I could not really tell from the oil if there was anything in it, so I put it back together, assuming the radiator cap. The second, just 250 miles later, it was very clear that the oil had coolant in it. I did the hoses with new silicone hoses while I was at it and that was by far the hardest part of the whole process and I would not do it again or recommend it unless you 1) wanted the pretty orange hoses really badly or 2) had a real problem with a hose. The seal itself was not that bad, once I got the screw eye in the ceiling and the chain hoist for the lifting. The old shaft was really worn, on comparison, but I was at 15k miles and it had probably been doing it for 1000-1500 miles before it finally got bad enough to turn on the overheating light when stopped (but it went off when I got moving). I saw no sand in the system. 2007 model. I have pictures of the coolant and old/new shafts if you want to see them.