I would imagine all of the 4 tee ones were the vacume side of things. The Heater core valve only has one vacume line, and it comes off that VSV. You can give the heater core valve vacume directly to test it. Sometimes the VSVs die too, and also you need that temperture sensor in front of the radiator hooked up or you won't get any heat either. I think there's a trouble shooting section for when you have no heat in the FSRM.