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Car has AC, Does anyone know if the 3 port vacuum control switches which are attached to the heater control are able to be restored. I have one that shows a part # 7301004-1 which doesn't seem to work properly. It appears to be partially plugged. Anyone know how to fix these or know a source for a replacement?
Thanks
Last edited by jrd1990zr1; Mar 22, 2022 at 04:25 PM.
Willcox has a tutorial on how to replace the vacuum selector switch plus connecting the vacuum lines to it. I don’t think they deal with repairing the vacuum switch.
Looking at the 68 HVAC parts diagram it calls out items #15 (Right Side) or #16 (Left Side).
#15 is part number GM #7302836 and should be the same for the 68-76 model years...
Both #15 & #16 are linked to Gr.8.850
Is it possible the switch you posted a photo of is NOT the correct switch?
i have never found a replacement for 16...the 59 valve has the simular crook in the adjust arm but has too many ports...thats why I was looking for how to test or rebuild the switch since it has three ports instead of nine
Looking at the 68 HVAC parts diagram it calls out items #15 (Right Side) or #16 (Left Side).
#15 is part number GM #7302836 and should be the same for the 68-76 model years...
Both #15 & #16 are linked to Gr.8.850
Is it possible the switch you posted a photo of is NOT the correct switch?
I am looking for #16 in the diagram you posted. The part # 7301004-1 is on the part and I have no reason to believe it is the wrong part #. My car is an October 1967 build (early car) and I know they used a lot of carry over parts from the 1967 MY. If someone has a different part number for #16 in your diagram I would be interested in hearing from them. When I apply vacuum to the system I do not get enough through the switch to open the fresh air vents. When I apply vacuum directly to the fresh air vacuum line the air vents open, so it has to be a problem with this switch. If I read your post correctly I think you are saying the switch is same either side?? I will check the right side to see if it matches the part number on your diagram.
i have never found a replacement for 16...the 59 valve has the simular crook in the adjust arm but has too many ports...thats why I was looking for how to test or rebuild the switch since it has three ports instead of nine
Do you have a 1968 with air? If so what GM part # is on valve #16?
Your best bet may be to restore/refurbish the original vacuum switches. Use Google to see if there is any information on the subject. Also, do a search for companies that restore/refurbish vacuum/HVAC controls for vintage cars. I found a guy in California that has the equipment to rebuild the old AC Fuel Pumps with the crimped covers.
#16 is a different switch but the other side of your switch also has a part number of 03246 A that is consistent with all of the replacement switches for Item #15.
Looking through some current e-bay listings for 1967 heater controls I do see the 7301004-1 vacuum switch on A/C controls of Impala, Caprice, Camaro & Firebird.
There is really nothing to these switches when you split them open.
Make a benchmark on the side of the switch of where the 2 or 3 half's started.
You would have to take a small cutoff wheel and grind the staked side of the rivet (port number side) off.
Purchase a 1/2 oz container of 3M vacuum grease a nylon pan head screw #6 or possible a #8? and nyloc nut.
Apply liberal amounts of vacuum grease to the vacuum passages on the inside of switch, apply just enough tension on new nylon screw/nut so you can still move the controls and still sealing switch half's together.
Scroll down to post #30 for a similar vacuum switch repair. https://www.corvetteforum.com/forums...-switch-2.html
#16 is a different switch but the other side of your switch also has a part number of 03246 A that is consistent with all of the replacement switches for Item #15.
Looking through some current e-bay listings for 1967 heater controls I do see the 7301004-1 vacuum switch on A/C controls of Impala, Caprice, Camaro & Firebird.
There is really nothing to these switches when you split them open.
Make a benchmark on the side of the switch of where the 2 or 3 half's started.
You would have to take a small cutoff wheel and grind the staked side of the rivet (port number side) off.
Purchase a 1/2 oz container of 3M vacuum grease a nylon pan head screw #6 or possible a #8? and nyloc nut.
Apply liberal amounts of vacuum grease to the vacuum passages on the inside of switch, apply just enough tension on new nylon screw/nut so you can still move the controls and still sealing switch half's together.
Scroll down to post #30 for a similar vacuum switch repair. https://www.corvetteforum.com/forums...-switch-2.html
1968 Heater control vacuum switch - HELP!
