the water pump puts water from the rad into the block, it comes back out the thermostat housing to the rad - usually there's a fitting on the water pump for a heater hose, that's the flow TO the heater, the return usually goes back to the head near the thermostat .... the best place to drain when flushing is the lowest point on the block, which may have a petcock on it, putting the water in can be done via the rad fill, flushing with the engine running
Bill
