Technical Brake Pressure Switch Issues

1950 Ford sedan.
The pressure switch was in need of changing out. It started working intermittently.
We tried two switches from different manufacturers. They bench tested just fine and by passing the switch and connecting the two wires to the brakes it showed the circuit was good.
Anyone have a suggestion or a well made switch that works?? Frustrating……

 

There was a post regarding this a bit ago. One or more after market vendors make this switch that is compatible with silicone fluid and the older Dot3. Might check that out. IIRC Dennis Carpenter might have been mentioned.???

 

Harley Davidson low pressure switch. I don’t have a part number, sorry.

 

Get an electric brake light switch from a modern car that is activated by the brake pedal under your dash. You can mount them easily using a simple 90 bracket. They stay dry and don’t require you to bleed the brakes when replacing them. If fact, I’ve never replaced one.

 

Thanks guys. I see now I’m the only one that has not ever had to change out a switch for 20yrs.
There are tons of info on the HAMB regarding this issue.

 

I found a source on eBay, they trip at 25 PSI and I bought 2. The 2nd is in the glove box, I haven't had to use it in 5 years.

I heard that Painless makes a quality one.

 

Ron Francis sells a quality switch replacement for about $35.00
I’v installed two and so far so good

 

Thanks for the post I had the same issues with my 53. I'm going with Ron Francis or Painless

 

Summit sells the Ron Francis switch

 

Dan Hay gave the best answer. Get a Harley Davidson one from a dealer not a Chinese replacement. The only other option is a switch on the pedal or a lever arm switch use on 50’s Chevrolet pickups.

 

I’m still using the original in my Fargo, I keep the old ones off of parts cars.

 

Plug the hole with pipe thread plug and add a good quality (NOS or old NORS) brake light switch from a 50s Chevy truck.

Here's my '41 with a stock master (I used a banjo bolt that didn't have the hole for the brake light pressure switch on the master).

 

Part number is ... 72023-51E

 

this AC Delco switch is available in left or right. they never go bad. As you see its a mechanical switch

 

+1 On the Ron Francis. I put one in mine and solved all my problems

 

Funny/odd thing I replaced mine twice in the late 70’s, early ‘80’s in my ‘57, but still used the original in my ‘59 for 6/7 years before I sold it in the mid 2000’s.
But I agree, dealing with a mechanical switch is the best way out.

 

Stick your left arm out the window, and direct your open hand toward the ground. It signals stop or slow to the car behind you I always use the standard brand when I buy a pressure switch. But normally I use the switch under the dash when I have the option.

 

Ya..in some parts of town that would draw shots.
Ya know, my first two daughters had to know hand signals for the DL test, my youngest wasn’t even asked to demonstrate it.
Heck, turn signals and and a second stop light were options at one time!

 

I bet today very few people would know what you were doing if you used hand signals.

 

I didn't know an actual pressure but I could tell that it takes more than just a touch of the brake pedal to trip the switch on the ones in my 2 cars.

Lynn

 

When I first built my roadster, using silicone brake fluid, I regularly went through brake light switches. I replaced them with a Harley Davidson brake light switch and the problem went away. I have had it on the road since 2009. The Harley switch lasted 10 years before it failed. I put another Harley switch and expect another 10 years of service.

 

And that includes some state troopers as well. My 83 year old friend got pulled over last month for not using his directionals in his '46 coupe. He told the trooper that he had indeed signaled his turn with his hand signal out his window. Trooper said that was not legal leading to a discussion that only ended when the trooper called his supervisor to verify the facts.

 

The Napa one that took a dump on me did work initially. The eBay replacement was advertised at 25 psi. The old one I had to practically stand on at the end for it to light up.

 

I put a standard replacement on my Plymouth, only to have a friend let me know that 90% of my drive didn't light it up. Pressure had to be full stop for lights to come on.
Converted to one of the chevy style lever switches, much happier with performance now. I have it adjusted to light up as soon as the pedal moves, so I can "blink" my brake lights without really slowing down.

 

Another for a gennie Harley switch.

 

To make a hyd brake switch last forever stop running Power through it. It's actually the arcing that kills them. Use a relay and make the switch do the Groundwork. No more arcing. Open one and you'll see they are just a reed switch with contacts. Even the mechanical ones die from the same issue.

 

Relays are GOOD.

Ben

 

We had a 57 that kept frying hydraulic brake switches. Fitted a relay , and never had a problem again.

 

I tried the arm signals for a short while. I got tired of people thinking I was waving at them

 

I had similar issues with the hydraulic switch, removed it and used this on firewall under brake pedal similar to post #12. easy to fine tune (Adjust)