Hey guys---on my 72 skylark 350, short piece of heater hose from intake to the diaphragm sprung a leak and I replaced it. Couple days later, go to turn on heat and it's blowing luke warm at best. Air bubble? It's not overheating when I drive it, no leaks and I topped off the coolant. Where do I start troubleshooting? I feel all the hoses when it's running and they are hot........ou: Gehmbo
Take out the flow control valve (diaphragm), replace it with a short piece of tubing to connect the ends of both hoses and check what happens. If you have heat again, replace the flow control valve :TU: PS: Is the vacuum hose still connected to the valve?
It has the heater control valve if it is an AC car. Feel the heater hose between the valve and the heater core. If it is not hot, it is the valve or it is in the pneumatic line that operates the valve. The contol line is the smaller tube that connects to the heater control valve.
