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Discussion Starter #1
I've found some vacuum pressure switches on eBay but not sure which to go with. Many seem to be designed for 120V AC... would these still work in 12V DC system?

Anyone have vacuum switch recommendations, or better yet, pics of their install?

Do folks typically connect their vacuum switches to a relay or directly to the pump?

Thanks all!
 

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I've found some vacuum pressure switches on eBay but not sure which to go with. Many seem to be designed for 120V AC... would these still work in 12V DC system?



Anyone have vacuum switch recommendations, or better yet, pics of their install?



Do folks typically connect their vacuum switches to a relay or directly to the pump?



Thanks all!
Look up a Hobbs switch. Lots of 12v options should come up. The switch should trigger a relay, since a vacuum pump draws too much current for that switch to handle.

Sent from my SM-N960U using Tapatalk
 

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Discussion Starter #3
Thanks for the reply. So are a pressure switch and a vacuum switch the same thing? My first thought is that they would be opposite and not interchangeable. Normally open switch, right? Only want it closing below 8 psi or something....
 

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Pressure and vacuum are not the same. S&S @ summit racing, and I believe chevy/ Mercedes(online search for vacuum brake) the OEM factory switch is a hall effect style. Both need a relay to power a vacuum pump motor
 

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Revisiting for posterity..

I found vacuum pumps (Bosch, Hella) and switches (Bosch, ?) in both Volvos and Audi/VW at the junkyard. The audi/VW switches appear to be better quality, and I got one of those. You can get the pump from the same vehicle if you like.. :). Haven't tested the components or set up the power brake system yet, but have sourced the parts.
 
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