I just finished changing my timing belt, pulley's and water pump on my 2000" Tundra and now the heat does not work. The t-stat is opening and there is hot coolant through the heater control and up to the heater core but the hose on the outlet side of the heater core is not warming up and no heat inside the vehicle. The engine temp. is normal and the radiator is full but still no heat. Any ideas?