I didn't expect to see that!

[JimC]

I got a call from my neighbor telling me that when he got home, he noticed that one of my brake lights was on. I assumed that maybe he meant my headlights, as I went to a cruise-in this morning and had turned my headlights on during the way home.

So I run out there, and check, and sure enough, it's the brake lights. One is on, and one is off. It looks like the replacement brake switch I put on there a couple weeks ago got stuck in the closed position. No worries, switches are cheap.

The highly interesting part though was the drivers side brake light. The bulb appears to have burnt out after being stuck on for several hours. In addition though, the very center of the brake light has experienced its own failure:



The very center of the brake light lens appears to have melted in. My best guess is maybe the combination of the oppressive heat we've been having, coupled with hours of baking from the bulb did it in. The bulb being burnt out sorta makes me wonder if when the bulb went out, it heated up more, and that was the straw that broke the camels back, so to speak. The hole is concave, going into the housing. It almost looks like someone pushed the hole in it, but I cannot imagine a way to do that without cracking the lens. This lens had a indent to begin with right at the point of failure, so who knows if that also played a role.

The other side (both the bulb and the lens) are just fine. I even gently pushed on the lens with my finger to see if it would cave in at all, but it didn't, despite the bulb being on until i pulled the wire from the switch a few moments earlier.

Has anyone seen anything like this before? A switch failing and a bulb burning out are fairly common, but I've never seen a lens fail like that.

[JEWELL]

I found both of brake lights on on my 64 Hawk and the lenses were hot as you know what. Turned out to be the brake light switch was bad. In your case though it was only one side of your car.

Mark

[63 R2 Hawk]

Some of the newer vintage style bulbs have a thicker buildup of glass on the crown of the bulb which acts as a lens to concentrate the light/heat like a magnifying glass would. I usually avoid using those ones as I've noticed they tend to concentrate heat on the lenses but never had a lens melt. Just curious, what type of brake fluid are you using? I have heard that silicon fluid can cause brake light switches to fail.

[StudeRich]

Yes I have seen many of them melted that way, the worst is my '58 President I am sure the reason it got melted is the Chrome plated pot metal Circle with star like legs going to the outside heated up, they are similar looking to the '63 Lark but not plastic.

Of course it only happens during very long trips at night or the time I wired the Tail Lights to the Auto Transport trailer lights and hauled it from LA, CA to Everett, WA.

Many times this is caused by residual pressure building up in the brake system due to a plugged vent hole between the Master Cyl. Bore and the Reservoir.

This can also be caused by a swelled brake Flex Hose at a Hydrovac Brake Booster.
It is not always the Stop Light Switch.

Another problem is the Bulbs in some models are too close to the Lens.
It would have helped if they had vented the Tail Light Housing somehow to allow heat to escape without filling with water.

[3rdGenStude]

I have heard that silicon fluid can cause brake light switches to fail.

My local NAPA store had a brake switch on hand for my '62 GT. But when they called NAPA to see if would be compatible with DOT5, they were told not to risk it. So they would only guarantee the switch if used with type 3 or 4. I bought a switch from the Harley dealer instead.

Paul

[SN-60]

All-in-all, hydraulic brake light switches can be a pain in the a--!

[JimC]

All-in-all, hydraulic brake light switches can be a pain in the a--!

Yup!

I've contemplated forgetting about the hydraulic switch and converting to a more modern brake light switch, but it seems like an awful lot of engineering for something that's only costing me $10 to replace. (Excluding the burnt out bulb)

I think the fluid in the brake system is the synthetic Valvoline dot 3&4 compatible stuff. I liked that it looks more stable and longer lasting on paper than traditional DOT3 fluid, but if it keeps killing my switches, I'll drain the system and go back to the old stuff.

Also, if anyone has a lens they want to sell, let me know. I don't want to pay the price of a new repop lens for my car, which is very much not a show car. A clean used one will do.

[jackb]

don't forget the M/C rod adjustment .....you must have "some" play in the brake pedal before it touches that rod......

[studegary]

,Also, if anyone has a lens they want to sell, let me know. I don't want to pay the price of a new repop lens for my car, which is very much not a show car. A clean used one will do.

I have a 1963 Lark & Cruiser tail light. The only "problem" is that it is the entire tail light assembly. I would still sell it for less than a repro. lens, but you should be able to get the lens alone for less than I would need to get for the assembly.

[JimC]

Many times this is caused by residual pressure building up in the brake system due to a plugged vent hole between the Master Cyl. Bore and the Reservoir.

Is this possible on a relatively new M/C? I purchased a replacement M/C early this year, and replaced it in early spring.

[StudeRich]

Yup!
I've contemplated forgetting about the hydraulic switch and converting to a more modern brake light switch, but it seems like an awful lot of engineering for something that's only costing me $10 to replace. (Excluding the burnt out bulb)

Hi Jim. tell me which it is please, either I am misinterpreting this statement or you are misunderstanding the simple and cheap Ford mechanical push plunger Stop Light Switch conversion on the '61 to '66 Larks, Lark Types and Avantis.

There is already a hole right next to your Brake Pedal Stop under the dash to mount a bracket with the switch and the stop light feed wire to the turn signal switch is right there going into the Column that needs to go to the new switch, it could not be easier!

I admit we have had more talk here about installing a under the floor Stop Light Switch for C & K Models and pre 1961's with through the floor Pedals which is a little more work, but still in my opinion quite easy.

[JimC]

Hi Jim. tell me which it is please, either I am misinterpreting this statement or you are misunderstanding the simple and cheap Ford mechanical push plunger Stop Light Switch conversion on the '61 to '66 Larks, Lark Types and Avantis.

There is already a hole right next to your Brake Pedal Stop under the dash to mount a bracket with the switch and the stop light feed wire to the turn signal switch is right there going into the Column that needs to go to the new switch, it could not be easier!

I admit we have had more talk here about installing a under the floor Stop Light Switch for C & K Models and pre 1961's with through the floor Pedals which is a little more work, but still in my opinion quite easy.

Well, it certainly would be the latter statement. I didn't realize that all of this was already done on the car. I must have never read a thread on that. I saw myself measuring distances, trying to drill holes in awkward spots, and all sorts of other things. If I don't have to do any of that, I very well may go that route.

Thanks!