[TR] Brake light woes

[Randall]

> Of course, this is assuming the switch is new, which is an absolute must!

So, you have to replace the switch every time you use the brakes?  

I've used DOT 5 for several decades now, and I love it.  The original brake light switch in my previous TR3A (which was converted in 1985 or so) lasted a long time, but eventually failed in just the manner described.  It would still work if the pressure was high enough, but the pressure required kept getting higher and higher until even a fairly hard stop would not light the brake lights.  Not a Good Thing.

Several replacements from various sources (including a repro switch from Moss and a Ford replacement from FLAPS) went the same way in fairly short order (less than a year for each one, some in only a few weeks).

Changing to a mechanical switch solved the problem permanently.  Well, almost permanently.  I did have one problem where the reservoir was leaking a tiny amount, and the fluif ran down the pedal and got into the switch ... causing a similar failure in a mechanical switch!  The moral seems clear, DOT 5 and switch contacts do not get along!  A post-mortem on the switch showed moisture along the shaft, which felt like DOT 5, and a hard black substance on the contacts, which I now believe to be silicon from burned DOT 5.

But having been pushed into it, I do rather like having brake lights that come on _before_ braking starts, rather than after.  With the mechanical switch, they come on as soon as I put my foot on the pedal, instead of waiting until the pedal has moved far enough to build pressure in the system.

Randall