I think the only thing you can do is check all of the hose connections and the expansion tank, and also check the temp sensor. The temp sensor leak is hard to see, but it can leak quite a bit.

To be honest, when doing the water pump, the tstat should done too. Depending upon how many miles you have, and time since it was last done, I'd do the hoses and temp sensor while doing water pump and tstat. It's not much money, and when one of those goes, they all tend to go.