GTD brake light switch

Simon · 05-24-04, 04:57 AM

Does anyone know what this was originally from?
My brake lights gave packed up. I've shorted out the two connectors (green wires) and the lights work fine so it must be the switch (see pic)

Paul W · 05-24-04, 06:26 AM

Hi Simon,

Chances are its a girling master cylinder and will take a standard sized switch. A friend of mine has made a bracket that fits above the brake pedal to hold a switch like production cars these days - alot more sensitive so lights come on alot sooner.

Howard Jones · 05-24-04, 01:17 PM

I did the same thing, I made a bracket that mounted a micro switch so that the brake peddle when moved off rest turns on the brake lights. The port can be pluged with a standard pipe plug 1/4"or 3/8" I can't remember which.

I believe a VW brake switch can be used as a replacement for the orginal pressure switch. I am sure if you take your picture, or better yet the switch itself, down to the parts store there will be a part there that will work. It is only a pressure activated switch, nothing special.

40 Bud · 05-24-04, 04:25 PM

I believe that GTD originally used a VW unit. Filko or Standard Motor Products have switches that work fine. Filko# SLS-24 Standard # SLS-27. Some of the older Ford pickup trucks used a similar switch and will take the pressure.

40 Bud · 05-24-04, 04:30 PM

Another thing to check is the condition of the bulb holders and the grounding. The stoplight assemblies use dissimilar metals and corrode easily, leaving you with a poor connection which results in weak or none existing lights. I added extra ground wires and Fred actually soldered his bulbs in place.

Malcolm · 05-27-04, 04:43 AM

The failure of this micro switch was a common problem with GTDs when they used the silicone based brake fluid. It basically corroded the contacts. The factory started to promote use of a micro switch on the brake pedal for people whose hydraulic switches had failed and changing over brake fluid away from the silicone fluids. Leave the old switch in place to block the hole (!) and make a simple bracket to fit a new switch over your brake pedal. I used a Ford brake switch and found it very straight forward to fit.

Peter D · 05-27-04, 08:36 AM

I just used a simple generic push-button switch actuated by the brake pedal lever - my mate at the auto-parts shop said it was "idiot proof".

Proof positive - I installed it & it still works months later !!

Kind Regards,

Peter D.
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David Morton · 05-27-04, 10:49 AM

I used a Harley Davidson brake light switch which is an hydraulic pressure switch and can be mounted anywhere it can sense pressure in a braided hose so it could conceivably be mounted in the rear brake line and use the same power source as the reversing light i.e. power to the gearbox sensor.
Dave M

Simon · 05-27-04, 11:10 AM

Thanks for the advice guys. I replaced the switch and it all works fine now. If/when it goes again (using silicone brake fluid) I'll replace it with something different.
Simon