Brake light switch

[Vinman1]

Hope all are doing well. Installing the brake system in my 1979 Seven. Using a Hydraulic switch. The only ones I find have a 1/8 NPT (pipe) thread and the 3 way is a 3/8 bubble flare. The MG and spit drawings show the threading right into the 3 way. Not sure if this is correct or what needs to be used to seal it? ie washer, thread sealer, teflon tape etc? Any inputs appreciated.

 

V

 

 

[MV8]

I think this is the correct part. It is not NPT and is bubble seat.

https://www.sportsandclassics.com/parts/british-other/sunbeam/sunbeam-alpine/lucas-hydraulic-brake-light-switch/

 

I'll add you will have a hard time adapting a male npt to standard brake thread and seats. I'm guessing you are not interested in engineering for a strictly electric switch operated by the brake pedal.

Edited May 20, 2022 by MV8

[Vinman1]

MV8,

 

Thanks for the reply. That will work, ordered it! I plumbed the system already, so rather than plug the hole, I figured I would hunt around for a solution. Google search turned up everything but what I needed, as is often the case. Thanks again,

 

V

[MV8]

If the correct part is not available in the future, it is possible to convert with two line adapters from 3/8-24 bubble to inverted thread, a 3/8-24 inverted thread tee, and this npt switch that includes a special adapter: 

https://www.speedwaymotors.com/Brake-Light-Switch-with-3-8-Inch-IFM-Adapter-Fitting,80727.html?NoRedirect=true&OriginalQuery=910-31304

[Vinman1]

I believe I found it at Moss Part # 560-480. Says tapered seat...