rocken Posted March 4, 2012 Share Posted March 4, 2012 I am working on a 54 Olds 88 with power brakes(treadle vac) there is a valve located in the vacuum line going to the vacuum reservoir that has an electrical connection on it, does anyone know where it should be connected at the other end? Should it be hot with the key on? or only when the brake lights are on? Also the license plate lights do not work. After investigating, the bulb sockets are mounted in a rubber gasket, looks original, how are they supposed to be grounded? Any help is appreciated!! Link to comment Share on other sites More sharing options...
rocketraider Posted March 4, 2012 Share Posted March 4, 2012 That switch came up in a discussion a couple years back but can't remember if it was here or classicoldsmobile.com. So- to our trusty 54 shop manual!The valve is solenoid controlled by the brake light switch and is designed to maintain vacuum in the vacuum reserve tank when the engine is shut off. With engine running, if manifold vacuum is greater than reserve tank vacuum, manifold vacuum will lift the valve's seat up and allow the reserve tank to equalise with the engine. The valve will then seat off until reserve tank vacuum is lower than engine vacuum. When the brakelight switch is energized, the electric solenoid opens the valve and allows reserve tank vacuum to the power brake diaphram. With engine shut off it will allow a couple of power-assisted brake applications.The other end of the wire connects to the brakelight switch on the power brake pedal. 54 wiring diagram shows feed to the brake pedal switch is hot at all times and fed off the battery junction block.On the license lights, make sure they're connected inside the trunk. They're in the bumper guards, right? Looks like they ground thru the sockets and to the chassis thru the bumper. Make sure there's a good solid ground path. Link to comment Share on other sites More sharing options...
rocken Posted March 4, 2012 Author Share Posted March 4, 2012 Glenn, Thanks for the info! I thought that was the way it should be connected, but since it wasn't connected anywhere, ya never know. As for the lights, yes they are in the guards, but are incased in rubber! If I touch a ground to the socket, they will light. The rubber looks like something that could have been factory, but not being grounded makes no sense! Thanks again!Ken Link to comment Share on other sites More sharing options...
Tedd Thompson Posted March 5, 2012 Share Posted March 5, 2012 Rocken, I remember soldering a ground to the license plate light socket on my 55 because I couldn't get a good ground or it was missing or corroded ( it's been twelve or more years since I did this). This took the problem away for ever, But I can't remember for the life of me why the original ground went bad but it sounds like a similar problem. By the way those license plate lens housings are hard to find in good shape and I don't think they are reproduced as yet...Tedd Link to comment Share on other sites More sharing options...
rocken Posted March 5, 2012 Author Share Posted March 5, 2012 Tedd, After more research, I found a small thin ground embedded in the rubber. Same thing, no contact, so I soldered it. Hope it holds, cause it looks like the bumper would have to come off to remove the guards to get at the license plate housings. Either that or someone with real small hands! Thanks!!Ken Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now