I'm in the middle of dealing with some virus hassles (I think - I don't run
Outlook at home so it might be something else...) but I'd like to comment on
this one before it gets away. Make sure that the switch you use mounts, like Bob
says, BEHIND (i.e. between you and the pedal) the pedal assembly. If something's
mounted in front of the assembly, then any limit on its travel might limit the
amount of brake you can apply, and that's bad. Toyotas (and I'm sure lots of
other cars) have the kind of switch you're looking for.
Theo
Bob Palmer wrote:
> Today Beckie and I took the rare opportunity to leave our kids home and take
> a tour through the local mountains with some other members of the Sunbeam
> Owners Group of San Diego, ending at a winery for some wine tasting, lunch,
> and fun conversation. The Tiger ran flawlessly the whole way, that is up
> until about 1/4 mile from home, at which point, following a loud pop, the
> brakes went very soft. I limped home and determined the problem was the
> hydraulic brake light switch had blown out. I don't know if a similar thing
> has happened to any of you, but it did happen to one of the participants at
> the Tigers United in Grants Pass in '95, causing him to rear-end another
> car. At the time I made a mental note to remove the hydraulic switch and use
> a mechanical switch instead. Well, finally, this evening I did just that.
> Just take out the Girling switch and replace it with a short 3/8" NF bolt
> (don't forget to use the copper gasket) and no more worries. Then, what you
> need to do is mount a mechanical switch directly behind (aft of) the brake
> pedal arm and adjust it so that it only has continuity (turns on) when you
> depress the brake pedal. I like the philosophy of this method over the
> hydraulic switch because your brake lights go on even before you have
> applied any real braking force, which gives the clown behind you just that
> much more time to react.
>
> I took the opportunity to cut open the switch to see how it was constructed.
> It consists of a rubber diaphragm, a spring and a copper button that makes
> contact with the two terminals. All this is held in place by some kind of
> potting material. If I had known how it was built, I probably would have
> replaced it sooner. The failure mechanism in my case was a short circuit in
> the unit which burned it pretty badly and caused the potting material to
> decompose. When I heard the pop and caught a whiff of the smell I was
> expecting a shorted cable and was reaching for the kill switch, even before
> I tried the brakes. Thankfully, I was going fairly slow up hill, not fast
> downhill as I had been doing a lot of earlier in the day.
>
> Sorry for the rant, but I thought some of you might appreciate being warned
> of this possibly serious failure potential. BTW, this particular switch is a
> replacement I bought from Sunbeam Specialties in 1986. I'm sure that time,
> heat, and abuse have played a role.
>
> Cheating death yet again in San Diego,
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