Mechanical Brake Light Switch

[DieselInfantry711]

Ok, not sure this constitutes a true modification but it is a slight upgrade to say the least. Now forgive me if this is beating the dead horse and if I have missed any threads that may have already addressed this, though I did a fair amount of research in order to prevent that but we make mistakes.

I got tired of replacing the Hydraulic Brake light switch on my deuce and didn't like the idea of putting in on my air line ( didn't want the added areas to leak and figured this would not be a good thing to lose brake lights when a sudden and entire loss of air pressure may be experienced) so my Father and I devised a mechanical switch which I hope is going to be fool proof and permanent.
Before I begin a full length thread on something like this I am hoping to see if anyone else has already done this so Im not. Anyone?

 

[A Blind Man]

I thought about Doing just that with a mechanical NC limit switch and bracket, so that it would engage right on the shaft of the master cylinder, (or rather disengage as soon as you moved the pedal approximately 1/8") but with a new air switch being $20 and considering that these switches are used on all sorts of heavy trucks, I took the easy way out... though I do have to say IMO a loss of brake lights will be the least of your concern when you lose air pressure... just my though

I can't say that I've seen someone on here do a mechanical brake light switch, but there are lots of build threads that I'm sure someone had to do it for one reason or another. (like switching the brakes from a/hyd to hydro or something else)

Do it anyways, it never hurts to have another person's take on a theme/idea

 

[porkysplace]

I thought about Doing just that with a mechanical NC limit switch and bracket, so that it would engage right on the shaft of the master cylinder, (or rather disengage as soon as you moved the pedal approximately 1/8") but with a new air switch being $20 and considering that these switches are used on all sorts of heavy trucks, I took the easy way out... though I do have to say IMO a loss of brake lights will be the least of your concern when you lose air pressure... just my though

I can't say that I've seen someone on here do a mechanical brake light switch, but there are lots of build threads that I'm sure someone had to do it for one reason or another. (like switching the brakes from a/hyd to hydro or something else)

Do it anyways, it never hurts to have another person's take on a theme/idea

A leak in a air brake light switch isn't going to cause you to lose your brakes in a instant . These are air assist brakes so you might start to lose the power assit but you will still have brakes . If you pay attention to the air gauge and a working safety buzzer it should be a issue . The biggest issue with these trucks are hydraulic leaks that lead to total brake failure due to the single circut design.

 

[winfred]

did it, el-cheapo threaded body brake light switch from phartz stoor on a metal bracket screwed to the floor where the pedal arm can contact it, crimp on bullet connectors fit into the original plug so no modifications done to anything except a couple bit tip screws through the floor

 

[DieselInfantry711]

I had an old micro switch laying around in my electronics junk drawer that I bolted to the floor underneath. When the arm I pushed down it breaks contact with the switch which I wired normally closed. I made a pigtail to go from the Packard connectors to the ring terminals so I didn't have to cut my original harness.
Found these Last brackets lying around and made a nice mount without any fabrication as the one has slots on both axes for adjustments. It triggers at approx. 1/8-1/4" of pedal. This way if I lose brake booster due to air loss and have a high hard pedal it still triggers. Plus it's hidden and fairly well protected from road spray and such.