Ther upper hose isn't at the water pump- - - -that's the thermostat housing. It delivers pressurized hot water to the heater core. The lower hose goes into the suction side of the water pump, and is the return line from the heater.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!