Brake light switch 4-way union

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peterc
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Re: Brake light switch 4-way union

Post by peterc »

Hi Roger,
Sorry if we are going round in circles on this one. Do you not already have a 4 way union. Where does your existing switch screw into?
If the better Automec switch is standard as UNF then you could screw it into a 4 way union from BGC as they definitely have them.
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Roger King
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Re: Brake light switch 4-way union

Post by Roger King »

The AC Cobra union has three threaded pipe bosses in a horizontal plane - one coming from the master, and one going to each rear caliper. The switch sits in a fourth, vertical, boss threaded at 3/8" UNF in the same union. Total of four - three to pipes, one for the switch. I need the same thing but threaded for a 1/8" NPT switch. I have not been able to find this configuration for any other car. Every MGB union I can find on the net shows four pipes and one switch. Correct thread, but one pipe too many.
Automec don't make switches, as far as I know.
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peterc
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Re: Brake light switch 4-way union

Post by peterc »

OK, understand so first issue is to obtain a decent switch and then plan to plumb it in.
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Roger King
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Re: Brake light switch 4-way union

Post by Roger King »

I have a decent switch. The Accel Harley Davidson switch, 1/8" NPT, as fitted to my Mini. Automec will now make me the union I need so the problem should be solved.
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Roger King
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Re: Brake light switch 4-way union

Post by Roger King »

I think I'm repeating myself here....
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peterc
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Re: Brake light switch 4-way union

Post by peterc »

Sorry I should have re read the thread.
So yes it was me that was going round in circles.
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Roger King
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Re: Brake light switch 4-way union

Post by Roger King »

Correct union now machined and supplied by Automec - hopefully now my brake lights will come on as soon as the Mini's do, under light pedal pressure.

Thanks for the idea, Peter!
IMG_3062.jpg
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David Large
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Re: Brake light switch 4-way union

Post by David Large »

My brake light switch does not work if I brake with very light pedal pressure. I have a warning light on my dashboard which only comes on with the brake lights, this helps me to manage the situation. It probably sounds like a daft idea but I am used to it and it does help.

David
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Roger King
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Re: Brake light switch 4-way union

Post by Roger King »

David, that is why I favour the Harely Davidson Accel switch, as shown in my photo. It is much more sensitive than the Lucas offering, both originals and repros, and I think therefore a lot safer. This was brought home to me on the Chairman's Barbecue jaunt on the Sunday, when I noticed how very few cars brake lights were coming on even when the car was obviously braking.
This switch, which has the same thread as an MGB/Mini etc. switch, would be a direct swap if it weren't for the union. It's odd that the Hawk/BGC union uses a 3/8 UNF with copper washer - probably all that was available at the design stage. But Automec can now supply the correct one!
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Re: Brake light switch 4-way union

Post by David Large »

I am very taken with your solution which is far better than mine. I will put it on my list of jobs which means it certainly will not get done this year!

David
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