Heater Vacuum lines
04-12-2008, 05:28 PM
#1
Drifting
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St. Jude Donor '08
Heater Vacuum lines
Before I stick the dash in I was going to replace all the vacuum lines on the inside of the dash. I ordered a vacuum hose kit and the lines arent the same. Mine are much smaller and vinyl, these are regular rubber. That doesnt bother me but the diagram that came with doesnt look anything like my setup. I thought maybe I got the wrong part, but I went and looked it up again on a couple of different vendors and they all sell the same kit for my 78 w/ac. Diagram also shows a hot water shut off valve which is not on my car, anybody else run into this?
04-12-2008, 05:55 PM
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Like you found, the factory vacuum lines under the dash are the vinyl tubes. Look almost like large gauge wires.
The heater cutoff is installed midway in the heater hose that goes to the intake manifold fitting. Sits just above the frame. A vinyl vacuum line attaches with a rubber connector, the other end disappearing into the wiper comp and then through the firewall to a vacuum switch.
The heater cutoff is installed midway in the heater hose that goes to the intake manifold fitting. Sits just above the frame. A vinyl vacuum line attaches with a rubber connector, the other end disappearing into the wiper comp and then through the firewall to a vacuum switch.
Last edited by KapsSA; 04-12-2008 at 06:01 PM.
04-12-2008, 06:36 PM
#3
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St. Jude Donor '08
Is the shut off valve required? or will it make the cabin hot in the summer? I looked on an old 78 truck and it didnt have one either?
04-12-2008, 07:16 PM
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A lot of guys replace it with a manual valve. I need to check one of mine. AC blows nice and cold til the Vette warms up. Must be the hot water flowing through the heater core.
04-12-2008, 08:36 PM
#5
Melting Slicks
This is what the original 78 looks like. Its metal and vendors sell them for about $45 or you can go to an Auto Zone and get a plastic one that works the same but looks different for about $12. The small tube is for the vacuum line.
Last edited by BKarol; 04-12-2008 at 08:47 PM.
04-12-2008, 10:53 PM
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I have 4 of them, they all go on the 5/8" hose to the manifold. I just replaced the upper hose on my white 79.
edit...page 172 in the 78 AIM
edit...page 172 in the 78 AIM
Last edited by KapsSA; 04-12-2008 at 11:04 PM.
