Damned BRAKE LIGHT SWITCH sucks in a dangerous way. Any better solution???

[terryb]

Craig911, would that thing fit inside the 3rd brake light on an '88 coupe?

[911pcars]

We kinda sequed from brake switches to brake lights.

Someone asked earlier about the early brake lightl switch. Here's a couple of pics from a spare.

The switch and the linkage to the MC actuator arm


This is the switch bracket. It's spot welded onto the pedal box.


Hope this helps,
Sherwood

[Formerly Steve Wilkinson]

Thank you, Sherwood, for your efforts. I'd asked wht the rig looked like, and you've made it very clear. I've got the OEM switch en route from Pelican, I need to fab a brakcet, and I now see that it's a release-pressure switch-off/lights-on rig rather than the reverse. Big help!

[Craig 930 RS]

I think it would fit in a 3rd mount brake light housing - !
-----
What is extra cool (after further 'testing' in the Turbo a la front window mount) is the sensitivity is adjustable in very small 'increments' - really a great design.

It is BRIGHT!

[madmmac]

Craig, I was wondering if they light up when going downhill, ya know, being a mercury switch and all.

I do like the idea though with the instant on for deceleration.

Thanks,

[Craig 930 RS]

They do - but just a bit. It seems that the blob of mercury takes a solid uphill travel before contacting - even downhill. I found that on steep (down) hills it does stay on, but almost always you are on the brakes anyway.

[Formerly Steve Wilkinson]

I just installed the above "motorcycle" brake-warning lights, and I think they're fabulous. Pretty much solves the slow-brake-switch problem, since they can be adjusted to come on virtually instantly any time you brake even a tiny bit...or conversely, only when you brake hard. I chose the former.

I installed two units--total of eight LEDs--on the underside of my whaletail spoiler, in the center, using industrial-strength hook-and-loop fastener, which is essentially very coarse Velcro. The angle of that area is such that it pretty much sets the units at their maximum sensitivity. My wife just followed me for a couple of miles and said they came on and pulsated every time I stuck my arm out the window to indicate I was about to brake, and that they cam eon at no other time, even going down our steep driveway and fairly steep, long Storm King Mountain.

And they are very bright from directly behind, which is the only angle I care about.

Thank you to Jack Olsen for pointing these out in the first place.

[Craig 930 RS]

Great report. Can you post a few pictures?

[JeremyD]

FYI - Daniel Stern has an LED 3rd Brake light too

http://www.danielsternlighting.com/products/products.html

[DaddyGlenn]

subscribed

[Formerly Steve Wilkinson]

Oh, jeez, I may have to replace my just-bought OEM chmsl unit. But them I'm about to upgrade anyway to a flush plexiglass rear window, so why not?

[JeremyD]

Where do you get spare switches?? (I guess I am talking about the ones on the MC).

Nevermind - found it on PET

[JeremyD]

Could this be the same switch? I googled the part number for grins and this came up?

and just to make sure I am on the right troubleshooting track

I cleaned and replaced the fuse for the brake lights (#7) sanded off contacts - no joy

Then I sanded off grunge on the lights - no joy.

License plate lights come on -

So, I am thinking that we have a brake switch issue. Correct?



So, can I replace with the MC in the car? I have a DE in two weeks.

[Formerly Steve Wilkinson]

Yes, you can replace the brake-light switch with the m/c in the car, as long as you make the switch quickly and don't let more than a little brake fluid ooze out--it's pretty viscous and doesn't really want to anyway. I've done it twice in recent weeks.

But I wouldn't bother; it won't fix anything. I tried it several weeks ago with two brand-new OEM switches, no difference in brake-light activation point. Then I "primed" my old (obviously perfectly functional) switches by dripping a litle brake fluid into the tiny cavity--which a poster had recommended--and switched the switches, as it were. That didn't make any difference either.

I have since bought ($80 from Pelican...) but not yet installed an early-911 mechanical brakelight sswitch that is directly activated by the brake-pedal arm. I need to fab a bracket to hold it.

As for the $3.75 VW switch you posted, it may well be a direct replacement, but at that price it's obviously Chinese. Your choice, of course, whether you want to put Chinese parts on a 911.

[JeremyD]

Ok, just to update this...

Yes, you can replace the switches with the MC in the car. Looks like they are 10mm fine bolt thread.

You need a deep 22mm socket to get to them, I found an offset wrench worked best.

I ended up doing this twice - It was still hard to activate the first time, so the second time I primed a little better with this...

sorry the picture is a little fuzzy.

basically it's a curved syringe I got for injecting epoxy. $1.49

After doing this - an carefully bleeding out the air - we have success - barely tapping the brake pedal and the lights come on now. Woo WOo - I might even pass tech now.

[sus911]

My attempt to prime the switches proved futile. Access is a problem, even with the fresh air vent hose removed. The proportioning valve needs to come off as well. I did a thorough pressure bleed after this and got improved results with the new switches, but in no uncertain terms ideal.
Interesting that the degradation occurred after the mc had been removed from the car then reinstalled so priming the switches MUST have an effect.