I had to replace the heater hosw that comes out of the water pump. After I had it hooked up, I refilled the radiator and started the engine. There was a little squeeling from the pump and the coolent did not circulate, the engine got hot. Up to this time, the pump worked fine. Does the pump need to be primed? I'm hoping that the squeel was from the belt slipping because the coolant had leaked on it. Any Ideas? I'd rather not have to replace the water pu,p but will if necessary.