One problem related to radiator hose has been reported for the 2004 Ford Explorer. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Ford Explorer based on all problems reported for the 2004 Explorer.
I own a 2004 Ford Explorer that has experienced two overheating incidents, the second resulted in replacing the engine. The first incident was caused by a stuck thermostat and the second by a leaking hose between the thermostat housing and the engine. In both incidents when the engine temperature warning activated, the temperature was buried in the hot end of the gauge. In both incidents, I immediately decelerated and pulled off the road but in the second incident, the engine was already ruined. An article in the April 2010 issue of design news (made by monkeys, pg 10) about a similar incident with a Mazda led me to believe mine was not an isolated occurrence but a result of increased use of aluminum and better cooling systems. In the Mazda incident, the engine had been replaced once and was saved from a second replacement only because the driver was looking at the gauge when it suddenly pegged into the hot end. The problem is there in no warning of low coolant until the level drops below the water pump which results in a sudden and often catastrophic rise in engine temperature. The Explorer is the most heavily instrumented automobile I have ever owned yet the cooling system warning is stuck in 60s when cars had cast iron blocks, overheated gradually and were forgiving of overtemps.