Engine Cooling problem
1998 Dodge Ram V8 Two Wheel Drive Automatic 114000 miles
my 98 ram 1500 5.2, has a leak somewhere around the water pump it only leaks sometimes, and only after the engine is turned off. It seems to stop after the pressure dies down. Worse on hot days, nothing to very small amount on colder days. My thought was a gasket, but ive never encountered a leak that is only present after shutoff.
Sounds typical of a leaking water pump seal. Sometimes cooling system pressure pushes on the lip seal and it seals better. Sometimes pressure pushes coolant past the seal. Some leaking coolant can evaporate or blow off, and sometimes it collects in a puddle that you don't see until after the engine is stopped.
The easiest thing to do is to use a cooling system pressure tester to vary system pressure while watching the gauge and looking for leaking coolant. An alternative is to add a small bottle of dye, drive the truck for a few minutes, then shine a black light on the area. The dye will show up bright yellow. You just follow it to the source of the leak.