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The line that went from the intake manifold to the fire wall had been repaired in its former life. The fix was not done correctly and the ?" copper line was a mess. Therefore, I decided to replace the ?" section. The 1/2 ' section was so extremely corroded that I could not tell if it had been nickel plated as well as the flange that bolts to the manifold

My question is what do I need to nickel plate and does the bulkhead fitting on the firewall get plated. Also, there is a vacuum switch on the bulkhead fitting. What is its purpose and does it get plated? Can it be tested to see if it works?

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Marston,

From what I've seen the vacuum lines and switch get plated. The pictures below show what I believe are original lines and fittings.

The vacuum switch can be tested. With the switch removed gently push on the black Bakelite button, and release it. You should now measure continuity across the two threaded terminals.

If you apply slight air pressure of 1 - 3 lbs. you should hear a snap. Remove the air pressure, there should now be no continuity between the terminals. If you gently press on the black Bakelite button again, you should feel a snap, and you should now have continuity across the terminals.

The vacuum switch is normally closed, it only opens on pressure, and is manually resettable.

I have never seen any factory / repair / or maintenance wiring diagram showing this switch.

My best guess is that it was put in to open an electrical circuit if the engine back fired. If it was wired between the ignition switch and Ignition terminal on the Startix, a backfire that may damage the starter bendix or jam it against the flywheel ring gear could be avoided.

Dave

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Dave,

Thanks for the photos they help me a lot trying to figure out how things should look. Your input on the switch on how it works is what I was kind of guessing. That's why that why I posted the question about it. When I pushed the button there was no closing of the circuit nor when I applied vacuum to the port.

It would appear that something be be either frozen up inside or the contact points are shot. I may try to take it apart to see what gives.

Again Thanks