So, I am replacing the water pump and thermostat on this truck. My friend has a vacuum fill kit, for the coolant, that he would lend me but I have no air compressor. He said that before he got that kit and there was no radiator cap on the radiator, he just would jack up the right front corner, where the reservoir is, and do a slow fill and had no air pocket problems and did not fill at the upper radiator hose. Anyone else ever done the coolant refill that way?