Thanks Neil. If I remove the lower hose, I'll have to remove the upper hose to get to it, so I might as well change all four hose.

Done. All 4 hoses have been replaced. Not a difficult job, but I did have a few challenges. Getting the lower hose off the heater core was brutal, even with the special tool. Removing the upper hose from the engine, and getting the new one on, was a nightmare. Thanks.