I have a 1993 Explorer 4X4. 4.0 Pushrod V6. It has been leaking coolant for a few weaks, so I put some leak sealer in it and it stopped for a couple of days. Now its leaking again, I cant see the leak, nothing hitting the ground. But I do notice , after the engine is hot and I turn it off, a hissing sound like water hitting a hot surface. (Duh). It seems to be around where the thermostat housing is, or on the very right side (passenger) top of the water pump, because I can see a small amount of water on it. Could i just need new hoses? Or is it the water pump? I am ruling out the thermostat because the upper hose is hot. Any suggestions?