when should i have vacuume through that line to the valve and how much? right now i have hardly any heat. i have flushed the heater core, changed water pump, changed thermostat and still hardly any heat. maybe the core is just too plugged still? i had heat prior to the valve breaking and spilling all my coolant. i replaced it with a "oem" from baxter auto parts. i just don't know where else to go beside that vacume line