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Need help with vacuum routing. My ac/heat only blows through the floor and dash vents. Everything under hood is new, everything under dash appears generally un disturbed. I've heard possibly a bad vacuum ball, or most likely incorrect routing. My vacuum ball has one purple line and one straight from the heat control valve (see picture). Is this correct?
132575
 

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On my 79. The purple one is right. The heater valve has a beige one going to it from the dash control. The other side of the ball is on the carb for vacuum supply to the ball.
 

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Not at home right now. In PA at deer camp putting out cameras and stands. I do have a couple of under dash pictures with the colors I told you. Not home until Monday. Should be 2 vacuum lines coming through fire wall at purple line. Mine was deteriorated and I ran black vac hose to them under the heater in the engine compartment. Took out pass inner fender to find them. C33C92A9-3746-4EA9-AAF3-C801B93EDE14.png 79E72831-F2B0-415D-AB59-D4DBB18D1020.png
 

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Discussion Starter #5
Not at home right now. In PA at deer camp putting out cameras and stands. I do have a couple of under dash pictures with the colors I told you. Not home until Monday. Should be 2 vacuum lines coming through fire wall at purple line. Mine was deteriorated and I ran black vac hose to them under the heater in the engine compartment. Took out pass inner fender to find them. View attachment 132578 View attachment 132579
Take your time. I have an unused vacuum port on my carb. I'm wondering if its supposed to "t" to the heater valve and vacuum ball. Good luck with the deer hunting. I started feeding a few weeks ago in CenTX.
 

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Routing is vacuum line off the carb to check valve, then to ball (some balls have check valve built in). From ball purple line to inside of cab controls. Grey (Biege) line comes from inside cab controls to heater control valve at heater core in engine compartment.
 

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For those of you working on vacuum lines for their air conditioning, NAPA is good source for replacement tubing. Use Gates 1/8" rubber fuel line (NBH H-174) to splice between bad or damaged original colored lines and air bag tubing which is black nylon (MBI D1020401) for longer replacements. It is best to retain the start and ends of the original colored lines to help with troubleshooting
 
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