My '66 Toronado headlight switch is leaking vacuum. I found this out during troubleshooting of the pop up headlights last summer. I recently removed the instrument panel to re-do the wrinkle finish that had long flaked away so I took the opportunity to have a look at the headlight switch.

I acquired a second, replacement, headlight switch not long ago just to have one as a backup or to replace mine. During testing on the bench, I noticed mine had 100% leakage on the supply port whereas the replacement one held perfect vacuum. I looked at the vacuum selector and realized I could just pop the old one off and swap in the one from the spare switch. Nice!

Yeah, not so fast. They're different. How could something like that happen? Seriously. This is a one year only part and even then, there's variations! I can make something work out of all this so it's not that big of a deal but boy is it ever frustrating.

As a side note, my original switch has little springs in the bottom that hold tension on the vacuum selector. They appear to be unsalvageable due to rust. Any thoughts on what I could use in place of these? I thought about maybe cutting up lawnmower recoil spring material.....any other ideas?

 

Corroded springs:


Two springs

Springs sit inside this plastic holder

 

Old ign points spring maybe?

 

Ugh you're giving me flashbacks...!!! These things are miniature nightmares. What about those press in spring clips on the back of picture frames? Or a hardware store would have the bent metal spring for window screens.

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I would also say that after being inside a '67 switch that it would be a good substitute for the '66, if needed. It looks like the same electrical connections, but it has a different vacuum port set up.

 

Pretty good ideas! I'm sure I can find something that will work.

I just can't believe that the little vacuum selector is different between the two parts. The vacuum selector is easily swapped between switches but I guess there are two designs, for whatever reason, and I was unlucky. God only knows when or why they did a redesign on it. Of course the one I received was a different design as well. These cars are an absolute pain to work on because there's so much of this kind of thing that you only find out about the hard way.

I can just straight up swap the switches but i wanted my original to work because I know the switch is good electrically. This replacement switch is unknown and knowing my luck, the vacuum side will work but the electrical won't. Anyway, I'll just keep working on it.

 

same goes for body molding clips. Ive got a couple parts cars and the clips are all different between them

 

I’d guess that the vacuum portion of the switch was made by Trico.

The sliding “sandwich” design reminds me _a lot_ of the vacuum power trunk lock switches I’ve played with. Have a look under my user name for my experiments disassembling these and my conclusion that they’re fairly easy to break. The good news is that what survives these failures is a spring steel shim which a lot like the one in your pictures. The plastics by now are pretty brittle.

I have no idea for the length or width of the Toro light switch spring steel shim which holds the plastic parts fast to each other - enough to create a vacuum seal - but I have a couple of suggestions:

1) Get a couple of vacuum power trunk lock switches from a roughly contemporaneous years. The shims in those switches are the same shape. And they just ___might___ be the same size. Or perhaps similar enough to serve as good source material to allow cutting to fit the Toro light switch. Poke around looking for Trico vacuum switches of that age and you might be able to find parts that will help.

2) Get a tube of “High Vacuum Grease”. It’s special goo that may allow parts to slide while maintaining a vacuum seal.

3) Get a mountain bike inner tube in case you need to make seals, or make a thick rubber sliding sandwich to replace the spring steel with a few thicknesses of rubber to force the plastic pieces together in place of the spring steel. If you go the replace-spring-steel-with-rubber route, you’re solidly in custom ground. I’d think of it as the route of last resort failing the ability to find/shape spring steel to replace the factory shim.

Hope that helps. I’m no expert I’m just spitballing…
Chris