58367 The $75 Junkyard Carrera coupe restoration

[Phil Planck]

Justin
Timely for me. I put a dual circuit on my PreA years ago. Got the kit from Klasse 356. This kit used the ATE M/C, and I assume the new owners still provide the ATE as their kit is quite a bit more expensive than Zim's. I called Zim's and they use the Brazilian M/C probably the one you have. I did install a mechanical switch on the PreA pedal assembly and have done the same for Foam Car. I uses a GM switch, but see that many use the 911 switch.


This pic shows the pedal depressed so the switch is activated. My method requires adding some more thread to the push rod for the actuation tab. The GM switch has a pretty fine thread so you can really dial in when the lights come on. I set mine for very slight pedal movement so I can touch the pedal without breaking if someone is too close behind for comfort.

[Don C]

Nice Phil. I used the 911 switch, a little pricy but I know my lights are activating! Added the CuLayer LEDs and a third brake light too, around here the people are distracted and clueless!

[Jack Staggs]

Justin, one of the issues with fitting a tandem MC is that the long line to the rear of the car is often too short to reach the proper port on the longer/different configuration of the MC. This may require an additional short length to be added on, and looks a little messy, at least to me. If you are fitting a new brake line to the rear, find one that is several inches longer than the stock unit, or make your own, to avoid problems.
In regards to brake light switches, the hydraulic ones work perfectly well and last decades, if a high quality (Bosch/Ate), of appropriate application is used. These excellent switches make contact at very low pedal pressure. If they do not, they are defective. We probably replace 3 or 4 per year on a customer base of appox 200 cars, a very low percentile. Of those we replace, most have seen service for a very long time.
If anyone thinks that pedal mount swithes are a panacea, they are mistaken. For one, clutch adjustment at the pedal box, a difficult proposition on it's own, will become nearly impossible with a pedal switch in place. I also have seen those switches have an intemitant short circuit, which can be difficult to diagnose when a fuse occasionally blows. Other issues include brake lights that don't light up, and brake lights that never go off, resulting in melted lenses. Bummer for beehive, where the bulb is closer to the lens.
I have never converted any car to a pedal switch in my 50 years of experience. All my customers seem happy. I must be doing something wrong with all the chatter about it.
A very simple test for brake lights is to turn the key to the on position, but do not start the car. Now slowly press on the brake pedal while focusing on the idiot lights. When they "wink" slightly (you have to look very closely), that indicates that the brake lights are on. If you can't do that, back up to a wall and watch when the lights illuminate while slowly depressing the brake pedal.

[Don C]

Hummm?

[Don C]

Why do ALL modern cars and motorcycles have mechanical brake light switches?
I Googled " hydraulic brake light switch problems" and found lots of interesting reading.
Your choice...hydraulic or mechanical.

[bbspdstr]

"You say tomato, I say tomato...let's call the whole thing off."

My last Speedster, my last race car, came to me with a mechanical brake light switch, wide silly fender flares to accommodate 7" wheels, coil-overs and ugly crude cooling duct passages through the panels from headlight buckets to the firewall in front of the fan hole on the engine. Those ALL went "back to original." (See avatar at left)

I must agree with Jack, I have never had to do more than replace a hydraulic brake light switch (of typical OLD "originality") with a new one to get balky brake light reaction back up to 'safe.' They clog, corrode internally, have corroded terminals and/or wire ends with high impedance or whatever....but it's difficult to 'better' the Porsche original design and specification.

Seriously, do whatever trips your trigger or lights your lamps. Both methods/systems work. All this pro-hydraulic stuff is from only two guys with merely 101 years of combined 356 experience, not the vast latitude of platitudes found online elsewhere.....

BTW, in racing, brake lights were often switched manually....on early before braking, off when actually braking...on when another car was coming up fast..."selective brake signaling"....or so I've been told.

"Brakes: if ya can't stop, ya shouldn't go."

-Bruce

[Phil Planck]

We're getting away from Justin's project, but will share my limited experience compared to Jack and Bruce. 3 sports cars all with failed hydraulic switches. Disected the first in a lab and contact points had gone bad. 2nd car had same problem. Happened to be doing business with switch supplier(Fasco) of the switch in 22nd car so they sent me 4 brand new replacement switches with test results for each. Quite a pressure range for switch activation. I installed the one requiring lowest pressure and it worked well till I sold car after 42 years of caretaking. Then the preA with ATE mc switch(unknown origin) started needing very high pedal pressure to activate. Almost got rear ended. Driver pulled up beside me and said I had no brake lights. That's when I converted to a mechanical switch which worked great for over 30,000 miles. With 3 for 3 issues on different cars I'm not going back to hydraulic. Your results may vary. Jack and Bruce are great contributors on this forum and to me personally. Unfortunately, I have been a light switch failure victim too often.

Phil

[bbspdstr]

Hey, I can rationalize at least one more pirating of Justin's thread, as I sent a care package to him today that involves his brakes....

Phil, your comment intrigues me -"Dissected the first in a lab and contact points had gone bad. 2nd car had same problem."

I had always thought of such dissection of "bad" switches but never took the time. If you will, please describe the contact points inside. Does hydraulic fluid occupy where those points (contacts) live or is there a seal backed by a spring that moves the points together for grounding. The opening 'in' is metallic, the power 'in' and 'out' is insulated...I'm just trying to think of that simple mechanism's construction and how it can go "bad" hydraulically...maybe points misalignment?... or corrosion and thus resistance to a completed circuit. Just curious.

Thanks,
Bruce

[Jack Staggs]

[quote="Don C" post=34798]Why do ALL modern cars and motorcycles have mechanical brake light switches?[/quote

Using Bruce's rational, I will add this (OK, stop groaning!!!). I suspect that the DOT had something to do with it. Some well meaning bureaucrat likely decided that it would be a good idea to have brake lights come on at the slightest touch of the pedal to give a momentary advantage to those following behind. Sounds reasonable in theory (they also suggested seat belts on motorcycles!) The problem is that in real application, folks that think that they MAY need to brake soon, often put their foot on the brake pedal slightly, illuminating brake lights needlessly, causing traffic from behind to ACTUALLY apply their brakes (kinda like Bruce's SCCA experience), creating a domino effect. I see this frequently on the freeways here. Studies have shown that this is a major factor in traffic jams and congestion on freeways. Other folks with automatic transmissions (more than 80% of new cars), use the brake pedal as a foot rest for their left foot, creating all kinds of havoc behind them. You've all been there.
Just today, I took an 8 mile drive and saw two late model cars with non operable brake lights. I have my doubts that all 3 or 5 or 7 bulbs burned out. Go figure...

[Phil Planck]

Sorry Justin for dragging this out. Bruce, I worked in an auto component supplier test lab the summer of 1964, so some details have left the gray matter for other stuff. We had a machine to slice open parts and examine them under a microscope, usually used more for metallurgy study.. With the switch, there was a rubber type diaphragm which had not leaked. A set of contact points that were similar to ignition. As I remember, they were pitted similar to ignition, only worse. This, I assume, caused the need for more pressure to complete the ground circuit. This switch was off of my 55 Healey. I don't knock Lucas electrics like many, as had only one incident over many years(horn relay on the 120 stuck and horn would not stop - same relay as the Healey's overdrive relay). Don't know who made this brake light switch. Anyway, we all have experiences that help drive our choices.

Phil

[bbspdstr]

"Anyway, we all have experiences that help drive our choices."

Yes. Truer words have never been bespoke. Justin was going to start a brake thread where all this would be appropriate, especially the link you sent to me individually. Just what I was looking for, thanks.

Don, Phil, et al, please don't take anything I post personally, especially my stubbornness as being of total allegiance to the hydraulic switch Porsche used on the 356, but I had trouble with a mechanical switch on one of my 911s so we just share experiences, as Phil posted above.

These cars were NOT supposed to still be around, so some parts (like a brake light switch of either type) will give us a little trouble once in a while..like every 20 or thirty years of so......

One thing is certain: of the many cars I follow in my daily trek to/from work on a super-ha!-highway have one brake light out, we can assume it's not the switch...but even one, two or three lights working is a traffic jam in the making. Thanks, Jack.

Thanks, all.
-Bruce

[JTR70]

Thanks a lot for all the great insight and suggestions on this brake light switch issue you guys. I'm certainly taking it all under advisement. And no, never worry about sidetracking a thread while expanding on a relative subject. That's how we all learn here.
Thanks again Guys!
Justin

[Bill Brown]

Hey Justin.......just curious, what wheels are you going to run?....bb

[JTR70]

Hi Bill,

I was originally going to these GT 4.5's up front with the deeper RSK 5's in back. However I have changed my mind (again) and have since sold this set.

Never really took note before, but a few 16 inch wheels came to me recently and during closer inspection and mock up I realized that I much preferred the looks of a 16 inch wheel center versus a 15 center. What does it for me is the vent opening profile. I love the more open and flatter profile as it must to reach the ID of a 16 hoop where as a 15 is scrunched and rolled quicker to squeeze into the 15 inch hoop. I was sold on the looks of this version the minute I stepped back

with my GT spacers in the rear. After seeing this no way was I going back to my 15's.

Here's a mock I did with those 15's right after I got the body painted.

Looked alright but it sure didn't knock my socks off like the 16's did.


Of course the problem here is that they are only 3.5 inches wide stock Not quite enough. So I'm in process now of having a set specially made that will be 5 inches up front and 6 inches out back with custom offsets for this specific application. Alloy barrels BTW.
I have seen that really nice set of original GT wheels you have for sale here in the classifieds Bill. A few years ago I would have been hot after them but as you can see I'm going in another direction.
Thanks! Justin

[Bill Brown]

Can`t wait to see those new wheels Justin! The car`s lookin great!.....keep it up.....bb