VACUUM SWITCH QUESTION

Ross Wooldridge

Old Man with a Hat
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Hey all,

With these 4 and 5 button vacuum controllers for heat/defrost/ac, it's my understanding from the articles I've read that there are plates that slide back and forth to allow vacuum to be applied to certain pathways within the system. Picture of a non-AC vacuum switch disassembled. Sliding plates are on the right.

1694279762335.png


From what I've gathered, the plates are lubricated with a Lubriplate style lithium grease, and of course, over the many years these things have been around, if not used they get sluggish or bound up as the lubricant hardens.

My question(s) is(are) this(these):

If everything else checks out with the switch (vacuum ports are in good shape, electrical connections are good etc.), is there a way to soften the lubricant that is already there rather than going to the risk of attempting to open the unit up? Opening the device involves drilling out or cutting the plastic bonding studs, and we've all read the "oops!" stories.

Can I spray into the ports a solvent that will work? Would it creep along and soften things up, especially if the plates already move, albeit sluggishly? Could I draw the solvent along with a vacuum pump?

Thanks in advance!
 
You could try spraying a lubricant down beside the push buttons, not in the vacuum ports, it may work. Premiumdashdecals.com in Kingston Ont. does a nice job rebuilding those switches. They can 3D print all those little plastic parts and make them work like new. They did a nice job on my 65 and 66 heater switches
 
Fluid film might be a good lube. find some other dry grease around garage or on car, see what lubes do what to the old grease before using on your switch.
 
If everything else checks out with the switch (vacuum ports are in good shape, electrical connections are good etc.), is there a way to soften the lubricant that is already there rather than going to the risk of attempting to open the unit up? Opening the device involves drilling out or cutting the plastic bonding studs, and we've all read the "oops!" stories.

Can I spray into the ports a solvent that will work? Would it creep along and soften things up, especially if the plates already move, albeit sluggishly? Could I draw the solvent along with a vacuum pump?
I would try CRC electronic cleaner. The thing is I would expect that it will work great for a short time and then the grease will harden back up, probably worse than before.

There's nothing to loose, so if you want to try that, don't put it in the car right away. Maybe a couple weeks on the bench, trying it every couple days and see what happens. I'm not overly optimistic about it working though.

I was going to link to the FABO thread on rebuilding until I spotted the pic was from the thread. LOL.
 
Maybe a graphite based lubricant after cleaning with the electronics cleaner.

From my limited experience, the fiberglass like pieces wear out and develop notches in them, preventing the passages to line up correctly.
 
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