Mechanical brake light switch

[850RS]

Thanks in advance for any info.

I’m switching to a mechanical brake light switch and I’m wondering if anyone knows the thread size and pitch for the switch? I want to design a bracket while I’m waiting on the part to arrive and I need to know what threads to design into the part. Any help is greatly appreciated.

Cheers

Here’s a link to the part I’m referring to.

http://www.minispares.com/product/Class ... o%20search

[Joel Welsh 4769VU]

The link you posted-
Has a link for the locknut for the switch.
If you get two of the lock nuts, you can possibly use them on either side of your bracket and wouldn't need to thread it?

https://www.minispares.com/product/clas ... 1903A.aspx

[LarryLebel]

If you're using silicon brake fluid I know the why reason you are changing to a mechanical switch. I'm using a Harley Davidson in-line pressure switch in my Traveller which is not supposed to succumb to silicon brake fluid.

[Exminiman]

If you're using silicon brake fluid I know the why reason you are changing to a mechanical switch. I'm using a Harley Davidson in-line pressure switch in my Traveller which is not supposed to succumb to silicon brake fluid.

Ohhh no, not a Silicon brake fluid discussion

[850RS]

Thanks for all the replies so far. The two nuts on either side of the bracket is my backup plan if tapping threads doesn’t work.

I’m actually using dot4 racing fluid as it’s a full on racecar. My reason for switching to the mechanical switch is actually to keep fewer wires going through the bulkhead and to prevent the need to bleed the brakes in the event that I need to swap out for a new switch. I’ve swapped a hydraulic switch before and didn’t need to bleed the brakes, but I have a KAD dual circuit setup on the racecar and I want to avoid having to bleed the brakes while at the track if possible.

[minibitz]

I’m pretty sure it’s 1/2” UNF thread on the switch. Putting the thread into the bracket is a great idea and would make fitting much easier. Trying to get that skinny nut to start with switch in position on pedal box is a right PITA!

[850RS]

Thanks Minibitz for the info. I’ll give it a go and see how it turns out. Once my switch arrives from minispares I’ll double check the threads and post a confirmation.

[Spider]

Sorry, I though this had been resolved. I did check a switch the other day and it is as Minibits suggests - 1/2" UNF.

[850RS]

Thanks Spider for confirming that. I have the part being laser cut and CNC bent as we speak. They won’t tap .100” thick aluminum with 1/2” so I’ll take care of that part myself when it gets here.

I made a template in cardboard and then transferred to fusion 360. I could have easily cut out and bent this in the garage, but I’ve been trying to get better with the software and learning the process of designing within the constraints of the CNC bending machine.

[850RS]

Just a follow up that it is indeed 1/2” 20 thread.

[Joel Welsh 4769VU]

Thanks for the follow up!
I was wondering how that had worked out for you.
Looks well done!

[850RS]

Thanks, Joel. It should serve its purpose well in the racecar.