Hydraulic Brake Light Switch

[TFB]

I was recently researching parts and came upon this negative product review for a hydraulic pressure switch for a brake system. It carries a very reputable name... ACDelco, but who knows if it's genuine or a knock off. Many parts are that way anymore.

Here's the part link
https://www.amazon.com/ACDelco-U855-...ustomerReviews

Since I'm in the process of overhauling a '39 setup on a '35, it got me thinking about this potentially weak link in the system. I know there's been countless discussions about single vs. dual systems, and the safety factor in redundancy. But this switch seems to me to be a big problem. They all seem to be made the same way, metal housing with a plastic insert that's then crimped over.

I've decided to try a '67 mustang MC setup which would be better if I used a pressure switch and had a failure I'd still have half a system, but I was wondering if anyone has used or knows of a conventional mechanical pedal switch setup that available? I don't know when Ford switched to that type switch but maybe that would be a better option. Thanks for any input.

[19Fordy]

Use the Harley Davidson hydraulic switch. They operate on low pedal pressure and last a long time. Do a search on Fordbarn.

[HD]

use a Harley Davidson switch, they are 1/8 pipe thread, same as early Ford, they come on as soon as you touch the pedal

[Tim Ayers]

Or get an NOS one from Fred @ Southside for $10.00 or so bucks.

[TFB]

Thanks for the comments, but I guess I didn't explain myself well.

I've also researched the Harley Davidson hydraulic switch, and yes 1/8"npt like the original. However I have found reports of issues with them also. Not exactly like the issue described above, but it's basically the same manufacturing method.

The main point of the thread was my concerns is with current manufacturing quality, and trying to move away from a hydraulic switch.

With parts made all over the world we've all have had experiences with shoddy parts.

However this isn't about the fitment of a trim piece, I'm basically talking about a plastic plug which is crimped in, over time fatiguing and blowing out.

Now maybe it will start to leak, and if noticed, it can be changed, but in the case above, he wasn't so lucky.

Does this point of failure give anyone else pause for concern? Or is it just me?

I mean, isn't this the way the story always goes??? Thousands invested and a lousy twenty dollar part put him in a ditch... or worst.

I've looked at Speedway's Brake Pedal Assemblies to get an idea of how they address the issue, but their pedals, which are made by TCI don't have switches, so I guess they use piped in ones as well.

I guess I could use some type of Lever Roller micro switch used in industrial applications

So any thoughts or experiences or pics of a spring loaded pedal switch install?

[Tim Ayers]

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Originally Posted by TFB

Thanks for the comments, but I guess I didn't explain myself well.

I've also researched the Harley Davidson hydraulic switch, and yes 1/8"npt like the original. However I have found reports of issues with them also. Not exactly like the issue described above, but it's basically the same manufacturing method.

The main point of the thread was my concerns is with current manufacturing quality, and trying to move away from a hydraulic switch.

With parts made all over the world we've all have had experiences with shoddy parts.

However this isn't about the fitment of a trim piece, I'm basically talking about a plastic plug which is crimped in, over time fatiguing and blowing out.

Now maybe it will start to leak, and if noticed, it can be changed, but in the case above, he wasn't so lucky.

Does this point of failure give anyone else pause for concern? Or is it just me?

I mean, isn't this the way the story always goes??? Thousands invested and a lousy twenty dollar part put him in a ditch... or worst.

So any thoughts or experiences or pics of a spring loaded pedal switch install?

The NOS one has the case crimped over the top to keep the plastic part in place. I'll try to get a pict.

[19Fordy]

TFB: Please post a photo of what you are describing when you say:

"However this isn't about the fitment of a trim piece, I'm basically talking about a plastic plug which is crimped in, over time fatiguing and blowing out."

The Harley switch on my 40 is 10 years old. I am using DOT 5.

A few more thoughts.
https://www.fordbarn.com/forum/showt...y+brake+switch

[TFB]

Harley Switch and ACDelco fail

Both are designed the same... plastic switch plug inserted in housing, then a die presses the end over the edge of the switch.

[Automotive Stud]

I've had countless hydraulic switches fail in recent years. I've been using GM style lever switches on the bottom of the toe board. Napa SL129 or BWD S191

[Tim Ayers]

Originally Posted by Automotive Stud

I've had countless hydraulic switches fail in recent years. I've been using GM style lever switches on the bottom of the toe board. Napa SL129 or BWD S191

I have one as well & was racking my brain as to where it should be placed. Of course, I didn't have the floor in at the time. LOL!

[JSeery]

Do your research on the dual-cylinder brake setup. They are difficult to install so that one half will work if the other half fails. There is normal not enough pedal travel for them to work. It can be done, but it is not just a bolt in.

[V8COOPMAN]

Originally Posted by Automotive Stud

I've had countless hydraulic switches fail in recent years. I've been using GM style lever switches on the bottom of the toe board. Napa SL129 or BWD S191

These are great switches....THEY WORK! Simple as it gets. Here is a picture of the switch mounted to the Ford's wooden toe board, with the brake pedal resting against the spring-loaded arm. DD










..................

[Aarongriffey]

Why fool around with those crappy hydraulic switches when EVERY decent parts store has the mechanical switches that A.Stud and Coop are showing pictures of?
There is a right hand switch and a left hand switch.
Either one will work on most pedals tha pivot below the floor.
I have one on my F1, I have one on my ‘48 Nash Ambassador and one on my ‘29 Nash and one on my ‘26 Model T Ford.
I also have two new spare switches. They are STANDARD SLS40 and STANDARD SLS43.
One is going on An MGTD that I am restoring an updating.
I can not be bothered with hydraulic switches, sespecially since my cars have DOT5 fluid.
Having worked in a bid gas station in St.Paul I’ve seen a lot of cars come in on the hand brake because the switch blew out.

[hotrodart]

Before you finalize your choice of MC.....I used a BOSS 429 MC (15/16" bore) on my '40 coupe (disc fronts).......I had to "section" the cover to clear the floorboard.....also had to lengthen the push rod by the thickness of the MC adapter mount......otherwise a great piece. I am told the Corvette MC will fit without modifying it......something to consider....

[Gary]

The HD switch is the most reliable and easiest to install

[Aarongriffey]

There has to be a reason cars have not come new with a hydraulic stop light switch for several years. They’re not safe!
The old Chevy/GM switches are easy to mount and wire.
Just two small screws or bolts through the floor.

[Aarongriffey]

I have installed Harley switches on some collector cars and have never known of any failures.
Just don’t want one on mine.

[35fordtn]

I've never had a issue with the new switches.... I did however have a NOS switch cause me to end up running a 39 Ford I had into a fence when it failed.

[Lawson Cox]

Originally Posted by TFB

I was recently researching parts and came upon this negative product review for a hydraulic pressure switch for a brake system. It carries a very reputable name... ACDelco, but who knows if it's genuine or a knock off. Many parts are that way anymore.

Here's the part link
https://www.amazon.com/ACDelco-U855-...ustomerReviews

Since I'm in the process of overhauling a '39 setup on a '35, it got me thinking about this potentially weak link in the system. I know there's been countless discussions about single vs. dual systems, and the safety factor in redundancy. But this switch seems to me to be a big problem. They all seem to be made the same way, metal housing with a plastic insert that's then crimped over.

I've decided to try a '67 mustang MC setup which would be better if I used a pressure switch and had a failure I'd still have half a system, but I was wondering if anyone has used or knows of a conventional mechanical pedal switch setup that available? I don't know when Ford switched to that type switch but maybe that would be a better option. Thanks for any input.

Hey. If you are worried about a blow out on a brake switch, go back to original mechanical brakes on your 35. Give us a break man. I've been in this hobby for over 50 years and have NEVER had a brake light switch "blow out" as you seem to be worried about. Fail to work electrically, yes. Leak a little, yes. BLOWOUT, never, and have never even heard of one blowing out.

[Tim Ayers]

Originally Posted by 35fordtn

I've never had a issue with the new switches.... I did however have a NOS switch cause me to end up running a 39 Ford I had into a fence when it failed.

Uh oh.

[35fordtn]

Originally Posted by Tim Ayers

Uh oh.

Yes, no kidding. I've used a NOS one since with no issues, but that was a scary moment

[Aarongriffey]

I saw a HeryJ blow a switch right where I was walking many years ago.
The car ran up on the trunk of fairly new Chevy.
One time an old lady in St. Paul was driving her ‘50 Plymouth down the corkscrew drive of a parking ramp when the switch blew out.
Fortunately she thought to pull the hand brake.
Having worked in the business since 1955 I have known of quite a few that blew out, however it is not a major problem, it’s just that it is easy to replace it with a mechanical switch.

[moonraker]

I don't mean to hijack the thread, but I have a related question. My brake light switch is acting strangely. It functions fine for the first 10-15 minutes of driving then quits. Brakes work with no issues. What can be possible cause of such behavior?

[TFB]

Originally Posted by Lawson Cox

Hey. If you are worried about a blow out on a brake switch, go back to original mechanical brakes on your 35. Give us a break man. I've been in this hobby for over 50 years and have NEVER had a brake light switch "blow out" as you seem to be worried about. Fail to work electrically, yes. Leak a little, yes. BLOWOUT, never, and have never even heard of one blowing out.

Thanks for your input L.C., you know 44 years ago when I got this car, and drove it without a care; I felt the same way that you do.

And as for mechanical brakes, I've collected those parts too, over the years; just to have them, but never intended to put them on because I don't think that is the safest system available to me.

However this is not 1976, and I'm not young and reckless anymore, I look at things differently now, especially when it comes to STOPPING.

Just because your 50 yr experience tells you it's highly unlikely I'll have a switch failure, that's not reassuring to me. My 40+ years in mechanical maintenance has shown me several things... parts fail when you least expect, part quality is subject to constant economic pressure and counterfeiting, and plastic has replaced several other stronger materials used over the years in manufacturing.

So you can't now say that you've never heard of a BLOWOUT, you see the above picture, you've read accounts of several members in this thread. I hope it never happens to you or anyone, but I can assure it won't happen to me because I'm not reinstalling one when I make my changes.

Larson obviously think that this is overkill on my part, you're entitled to that opinion, however I won't (as you say), "give you a break" unless you give me a break and realize that just because you're not bothered by an hydraulic switch on a single MC system, it doesn't mean the potential for a catastrophic failure caused by a $20 part doesn't exist, or the concern isn't real.

As for this mod, since I'm starting fresh with this, I'll consider all the helpful information that's been provided, including the alternate MC choices suggested, I'm grateful for all the input. Thanks everyone.

[Karl Wolf]

Originally Posted by Gary

The HD switch is the most reliable and easiest to install

I just replaced a HD. switch that stuck closed- they're not perfect.
This is on a stock, electrically unmodified 2007 Dyna, under 10k miles

[TFB]

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On the topic of MC choice, I realize there are trade offs concerning bore sizes. I mentioned the Mustang 1" bore earlier because many who changed went in that direction. However there are reports that if you lose one half of the system, the limited pedal travel in these early fords will not provide enough braking in the remaining system half before you run out of pedal.

So I'm researching other options like the late '70 E250 Econoline which has a 1 1/16" bore like the single MC, but a larger body. I don't know how that will fit, but we'll see.

I'll post a thread as I proceed with the project. Thanks All!