Newell Gurus

I recently had the water pump changed since it started leaking. Since then I drove it to Cedar Key, then over to Silver Springs. Now I'm in Summerdale, AL about 900 miles of driving since getting the water pump changed.
A couple days ago in Silver Springs I noticed the coolant overflow tank was almost empty so I added 1/2 gallon coolant. When I pulled into Summerdale the coolant tank was almost empty again. I just looked all around the engine and hoses, in all of my basement compartments, and anywhere else I thought I'd maybe find a gallon of green coolant that leaked out. Nothing!
Engine oil looks good and hasn't been growing, tranny fluid and power steering fluid both look clean.
I was thinking maybe I have an air bubble that is just now working out of the cooling system but just want to make sure I'm not overlooking anything important.
I just added water to the overflow tank to see if it leaks out there while I'm sitting for a couple days.
Any ideas?

Sounds like the air bubble has worked itself out. When i bought my coach a couple years back, I changed the air compressor coolant hoses. Fill the coolant many times before that pesky air bubble went away.

Forest,
If the problem continues, I would close off the 4 valves on the engine that allow coolant to go forward. When I changed my pump a year ago, I closed off all of those lines & have never had to add coolant.

those valves are 2 out and 2 return lines for the hotwater heater heat exchanger, the bay hot water radiators for heat, the one at least on mine that is under the bed and the dash heater. one set goes likely to just the hot water heater and the other set to all the other things.

good way to find out if the leak is forward of the engine, but if you want any of those things to work, then you will want to turn them back on.

tom