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

[Brillo]

Originally posted by Formerly Steve Wilkinson
Interesting! And I thought I was the only one who had this problem. Even installed a new switch, no improvement, was beginning to worry that I had something faulty.

Same here.

[Formerly Steve Wilkinson]

Okay, so _nobody_ has an opinion whether or not the entire problem is due to failure to "bleed" the brakelight switch before installing them? That'd be a first.

[Wil Ferch]

Steve:
Okay then....The premise makes sense....air is compressible...a liquid fluid is not ...and would hydraulically transmit forces better/more directly. So a bleed might be in order...how would you do that and not lose the fill while installing?

Jack O...nice find...

Andrew..also nice...the switch is "pushed in" in the static normal position and is "allowed-out" upon brake pedal pressure....has to be very effective and quick, especially since you can probably adjust the position of the switch and therefore its sensitivity...when it activates. I would try to hide/protect the wires a bit more, though.

-Wil

[pmajka]

Yes, failure to bleed the Wet switch...I put new ones in and same results...but, am betting there is a bubble.

[Formerly Steve Wilkinson]

Wil, I should think you could pop the switch into place quickly enough that no fluid would run out before you got a thread engaged, since it's moderately viscous. I'm gonna try it.

[911pcars]

Originally posted by Formerly Steve Wilkinson
Wil, I should think you could pop the switch into place quickly enough that no fluid would run out before you got a thread engaged, since it's moderately viscous. I'm gonna try it.

.... or have a helper slowly press the brake pedal to create positive pressure in the MC as you R&R the switch. That way, air (and some fluid) is expelled during the process.

I'd think seriously of using a mechanical switch if pressure switches present this much of a hassle (non-adjustable, limited life).

Sherwood

[madmmac]

I have an 84 which precludes the 3rd brake light and would be interested in the battery operated (no wiring) motorcycle led's.

Has anyone tried them?

[Won]

Stephan, please let us know if bleeding the switches makes any difference, I'm very much interested! I would think the viscosity and capillarity would keep the fluid inside the bore.

My mechanical switch is set up so that the lights would turn on just as the slack in the pedal bushings and linkage are taken up. I would much rather have it come on too early than too late.

[Formerly Steve Wilkinson]

Won asked me to report back on my experience with "bleeding" the brake-light switches before installing them.

Bad news: makes no difference.

I had a pair of good switches among my spares, so I dripped brake fluid into them and left them on the workbench for an hour, sitting erect (of course), to ensure that the fluid went into them. Even prodded them gently with a thin wire to ensure that there wasn't a trapped air bubble.

Pulled the old ones out and instantly installed the new ones before the brake fluid had a chance to run out--it's viscous enough and in a small enough hole that it really doesn't want to run out anyway--but it made no difference to the brakelight-on time.

It was also obvious that the switches I pulled out were full of brake fluid--no trapped air bubble either.

I'm goin' to a mechanical switch. I've also ordered a pair of those motorcycle inertia LED clusters that Jack Olsen led--no pun--us to.

[jester911]

I swapped mine out a couple years ago the same way formerly Steve did. They are just about back to the way they were before.
It takes more and more pedal pressure over time to activate.

I am about ready to do a mech switch as well.

[JeremyD]

Mine takes more effort too - especially with 993 calipers and a 930 MC - I'd love to see an easier solution to this!

[Craig 930 RS]

For me the problem is two-fold:

1) Brake lights are too dim. No real solution for this - the LED deal realistically isn't that feasible or efficient.

2) Brake lights come on WAY too late and with too high of pressure - aka too hard/quick stop - required.

I plan to rig up a durable manual switch for the brake lights - ALONG with the inertia LED setups that Jack mentioned. Mine shipped today.

A 9XX that is rear ended....is often a total.

[Jack Olsen]

Any redundant solution is a plus. And I like Andrew's switch since when it fails the lights go on, rather than a failure where the lights don't go on. If Andrew's switch could be wired in parallel with the pressure switch (so that if either failed the other still triggered the brake light), I think it would be a big improvement. Any switch down by the pedal cluster that I could cause to fail by deliberately kicking is a no-go, in my book. Over time, lots of stuff can bounce around down there.

I bought the LED/inertia switch unit a couple of years ago. I actually bought it as a brake indicator for in-car videotaping, and put it somewhere... I have no idea where it is now, and I never ended up using it.

[Formerly Steve Wilkinson]

One semi-solution for the dimness of the brake lights--I have LEDs in RS taillights, but they're not for everyone--is the OEM later-model CHMSL, which I've also installed. (Pelican provided it.) It's pretty bright. A lot of people think they're dorky, but I think a rear-ended 911 is even dorkier.

[john walker's workshop]

german switches work better than brazilian ones.

[Formerly Steve Wilkinson]

Can the OEM non-power-brakes mechanical switch be fitted to a power-brakes car, i.e. an '83 SC? It's $80, so I don't want to spring for it without knowing... I don't like the kludge arrangements that have been posted here and elsewhere, and for the same reason Jack Olsen doesn't. Besides, they might be Brazilian...

[Ken911]

I had this problem on my carrera replaced the switches didnt do any good flushed brake lines with the power bleeder and the problem went away I think a small amount of air got trapped in the line near one of the switches.

[xlr8]

Dim Bulbs?

I replaced my original bulbs with 3496 krypton bulbs.
In the pics below the top pic is the original bulbs, the middle pic has the left bulb replaced and the bottom pic has both bulbs replaced.

bulb comparo



This website has a desciption of using highly reflective tape in the lens buckets to increase candlepower.
I have not tried the tape yet.

[john walker's workshop]

the early mechanical switches attach to a bracket on the pedal cluster housing which is not there on the later ones. so fab a bracket for it.

[terryb]

Russ, where did you purchase those krypton bulbs? Are they just drop-in replacements? Details please! The referenced site is pretty Chevy focused.

Thanks.