Electrical: After a long winter's nap....

[Tom Bredehoft]

Getting the '55 out for summer fun, the brake light doesn't work. I made sure the connections to the switch were secure, no joy. Put a 'channel lock' on the switch, still no joy. it won't come out. "Course me lying on my back on a creeper, under the jacked up car didn't help.

Can I pretty sure that the switch is bad? It was new half a dozen years ago. The running/parking lights work, as do the flashers. Just the brake light fails to do its job.

Yes, I have Dot 5 brake fluid in it. I know. Dot 5 eats brake light switches, that's why I'm asking.

[rstrasser]

Tom B;
There should be two wires on the brake light switch.. Join them together; if the brake light illuminate the switch is bad. Either replace it or install a different switch that operates off of the brake pedal.
Ron

[jclary]

Replace the switch. Some time ago, I had a thread about this very subject. I cut a defective switch open to reveal the problem. The problem is corrosion internally on the supposedly dry side of the switch. When I say "supposedly dry side," I believe that the switches are manufactured/assembled in regular air. If they were assembled, and sealed, in a chamber of inert gas, I don't think they would corrode.Since this is a pressure switch, the electrical chamber has one side a live wire, and the other side a ground, I believe, over time, the air between the contacts turns somewhat conductive. At least conductive enough to promote ionic corrosion. The very small amount of corrosion at the contact points of the switch are enough to keep the switch from working.

Here's the pic. Click on it to enlarge. You will notice that the two contacts are half corroded across their face. The copper wafer is the "contact bridge" between the live wire circuit, and the ground circuit that goes to your lights. The spring is the "stand-off" that keeps the wafer pushed back until pressure is applied from the "wet" side. You will notice that the corrosion on the copper wafer, matches the corrosion on the smaller contact points for the individual wires. A very simple device...works great...until corrosion wipes it out.

[karterfred88]

Getting the '55 out for summer fun, the brake light doesn't work. I made sure the connections to the switch were secure, no joy. Put a 'channel lock' on the switch, still no joy. it won't come out. "Course me lying on my back on a creeper, under the jacked up car didn't help.

Can I pretty sure that the switch is bad? It was new half a dozen years ago. The running/parking lights work, as do the flashers. Just the brake light fails to do its job.

Yes, I have Dot 5 brake fluid in it. I know. Dot 5 eats brake light switches, that's why I'm asking.

If it were me, I'd touch the two connectors at the switch together-brake lights-new switch. Then figure a way to install a simple pedal operated mechanical on-off switch. problem solved forever. I'm sure there is a past post on doing it on the below floor linkage of a C/K.

[64V-K7]

If you're using DOT5 and are worried about the fluid getting into the switch and shorting it out..... Fill the switch with regular brake fluid before installing it.... OR install a mechanical switch..

[doofus]

Worked in private collection/resto shop for years and switches would go out whenever they felt like it. vehicles, 65 of them were driven fairly regularly to meets and parades and such. no rhyme or reason, they would just go bad some were new some NOS some were even used.even tried warming some with hair dryer/heat gun as we cut one apart years ago.all commonly driven Studes had a switch in glove box and channel locks under seat! go figure. Doofus

[jclary]

Worked in private collection/resto shop for years and switches would go out whenever they felt like it. vehicles, 65 of them were driven fairly regularly to meets and parades and such. no rhyme or reason, they would just go bad some were new some NOS some were even used.even tried warming some with hair dryer/heat gun as we cut one apart years ago.all commonly driven Studes had a switch in glove box and channel locks under seat! go figure. Doofus

Well...on my part, I think there is a reason. (And for full disclosure, this is pure speculation.) But, I suspect that these switches are built and sealed up in regular air (atmosphere) exposed to what ever the concentration of general elements, humidity, and barometric pressure exist in the room they are being assembled in. Someone might want to research this, but I believe if the switches were assembled in an "inert gas" filled chamber, such as Nitrogen, or Argon, there would be no potential pollutants to promote corrosion of the contacts internally.

In my opinion, the reason the switch failure is so unpredictable, is due to the huge swing in ambient atmosphere elements on any given day. Humidity, temperature, Oxygen, natural ozone, dust, etc., vary widely when no "clean-room" control is in place. Anyone with knowledge of how these switches are actually manufactured/assembled? If so, your input would be greatly appreciated.

[Commander Eddie]

Well John, I figure that every time they put the assemblers in a room filled with Nitrogen or Argon they all die.

[karterfred88]

This is an interesting study of why they fail-not fluid related at all. http://www.sw-em.com/hydraulic%20bra...es%20notes.htm

[Tom Bredehoft]

Update, I was scheduled for two new tires today, so I took the new brake switch with me. It seems it would cost $98.00 to install. Thanks anyway.

Having not solved the brake light problem, I forgot to tell them the lug nuts on one side were left handed. My Bad. They stripped four of them before they thought to tell me. After 3 extra hours they were replaced, but I don't know if left or right hand. I wouldn't be surprised either way. They also re-greased the wheel bearings while they were there, no charge.

Fred, thanks for that link, it certainly seems reasonable. If the chamber were filled with Argon there would be no oxidation happening, but what other reactions might there be!

Update further: They replaced 5 lug bolts on the left side of the car with Right Hand screws and nuts. I wish I'd witnessed the removal of the old ones....I'd put them in 6 years ago.

[jclary]

Well John, I figure that every time they put the assemblers in a room filled with Nitrogen or Argon they all die.

I have had several customers assembling parts in an inert gas filled chamber. The term "Clean room" covers more than a mere room in a building.

However, several years ago, in a local manufacturing facility that manufactured carbide cutting tools, there was a tragic accident regarding inert gas use. There was a huge steel pressure chamber used in their processes (details I don't understand). It needed cleaning. One employee, entered the tank to do the cleaning and became overcome due to the lack of oxygen. A coworker witnessed the first guy having difficulty, and went in to help him.

Tragically, they both were overcome and died. I think the outcome of the following lawsuit was that the plant was charged with negligence in failing to properly train the workers in how to "purge" the tank before entering. I believe it was settled out of court. But, you are right, not properly controlled...it can be fatal.

[jclary]

This is an interesting study of why they fail-not fluid related at all. http://www.sw-em.com/hydraulic%20bra...es%20notes.htm

That is a great article. Finally got a chance to read it. ( As we know, "read" and comprehend are two different things.) But, the heat, arcing, close proximity of contacts, travel variables from degree of pressure applied, etc., make sense. Unless I missed it, he does not cover my theory of airborne contaminants. While I believe all the writer's conclusions are valid, I still believe the switches would last longer if sealed in inert gas. Keeping the contacts free of oxygen and other contaminants, would make arcing much less likely, and extend the life of the switch. That's why we use inert gas in wire feed welding, flux coatings on welding rods, and flux paste soldering.

This a probably much more discussion and clamor than the subject deserves, but I believe it explains why the switches fail.

Back in the days when we could buy a new switch for three bucks, young enough to fall to the ground, crawl under the car, screw the old switch out, pop a new one in, slide out from under the car, spring up, with a grin on our faces, eager to tackle another problem...it was a "piece of cake."

Now...a little more challenging task!

[karterfred88]

No it doesn't cover airborne contaminants, because, I think, he shows that the arcing of the electric contacts causes the failure. Since arcing in this design will happen even in a vacuum, the design itself is the cause of failure. Slow arcing contact, release, slow arcing separation, equals heat. The unit he shows is much more robust than the one you cut apart, there being a substantially thicker moving contact part. It didn't need corrosion to fail, I think the corrosion speeds it up though. I understand the installation hassle all to well, that's why I think a mechanical switch is the way to go.

[rkapteyn]

These are the correct solution.

http://www.studebaker-info.org/tech/brakes/sdc34736m.html

http://forum.studebakerdriversclub.com/showthread.php?78407-Mechanical-Brake-Light-Switch-Install

Robert Kapteyn

[Mikado282]

Update, I was scheduled for two new tires today, so I took the new brake switch with me. It seems it would cost $98.00 to install. Thanks anyway.

Having not solved the brake light problem, I forgot to tell them the lug nuts on one side were left handed. My Bad. They stripped four of them before they thought to tell me. After 3 extra hours they were replaced, but I don't know if left or right hand. I wouldn't be surprised either way. They also re-greased the wheel bearings while they were there, no charge.

Fred, thanks for that link, it certainly seems reasonable. If the chamber were filled with Argon there would be no oxidation happening, but what other reactions might there be!

Update further: They replaced 5 lug bolts on the left side of the car with Right Hand screws and nuts. I wish I'd witnessed the removal of the old ones....I'd put them in 6 years ago.

This is just an example of people no longer being able to independently think as opposed to doing things by rote. On the very first one I would have stopped and tried to figure out what was wrong. This is what we are trained to do and it must be right, I doubt if Apollo 13 were to happen today using the technology of the day the crew would have never made back to earth, let alone alive. A sad situation but true in today's world