[T3] DOT5 and Brake Light Switches

[Jim Adney]

On 14 Jul 2016 at 12:46, Sean Bartnik wrote:

> So far I've been through two new FTE brand switches (the $20 ones) and
> a NOS Ate switch, all of which failed in the same manner within a
> couple months. 

My '69 Square has DOT-5 and was stored for 14 years before I got it 
out and prepped it to drive to the 2016 Invasion. It had a number of 
problems, but the brakes were completely trouble-free. The brake 
light switches on it appear to be 2 different versions of Brazilian, 
but I can't be sure because they haven't been touched in probably 15 
years.

It's clear that we have a brake switch problem. What's not clear is 
whether DOT-5 is part of the problem. I've cut apart a number of 
failed switches to see if I could pinpoint a cause. I've never found 
brake fluid on the wrong side of the rubber diaphram and I've never 
found a diaphram that was swollen or damaged in any way.

I've seen a few switches with a melted plastic part that should have 
been metal and Dave Pallo had one that he bought from me that was 
simply improperly made.  

I'm surprised that the FTE (formerly FAG) switches failed. I thought 
those were supposed to be good. NOS is not always a good choice, 
because some parts degrade just sitting on the shelf. Switch contacts 
may degrade if not cycled occasionally.

We went thru the (made in China) Meyle problem, where the pinouts 
were wrong, but even when they fixed that, their failure rate was so 
bad they stopped making them there. Meyle switches are now made in 
Spain IIRC, but they no longer import them into the US. That's too 
bad, because they claim their failure rate is now excellent. I have a 
small number of the Spanish Meyle switches if you want to try those.

Frankly, I'm stumped, but I'm not convinced that DOT-5 is part of the 
problem.

The Harley switches sound like a good solution for '67 and earlier. 
For the later cars, I'd like to preserve the 3-pin configuration, 
even tho the warning light is a pretty worthless feature.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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