I have a 1955 ford customline fordoor that was originally a 3spd manaul but was later converted to an auto. I'm not too sure if it matters between the two. So I was looking at the brake master cylinder and decided I want to update older parts. If I convert it over to the newer style BMC would I have to run a different brake switch that's connected to the brake pedal? Or would it be easier to replace the older switch and keep the older style cylinder? The first picture is what is currently there. The second one is what I'd upgrade to which you can see has no switch on the end. Thanks again.
If the one on the pedal (mechanical switch) works, leave it. If you change the M/C just plug the hole where the hydraulic pressure switch would sit.
I got tired of buying those pressure switches after 2 or 3 failures. Now I use a cheap motorcycle switch rigged to the pedal and it works great. Many ways to go.
I use a CPP distribution block that has a Ford type pressure switch on my Ford. Summit sells them too. My personal opinion, avoid using combination valves made for more modern cars. Going back to my old dual master conversions, I just used a tee to split the rear and front circuits. I had to replace my pressure switch 2x. The Napa one I had lasted a month. I found some that trip around 25 psi on eBay that work well. I have carried a spare for years now.
Harley-Davidson has a hydraulic brake light switch, P/N 72023-51E and it’s compatible with DOT 3,4 and 5 fluids.
If the brakes work now leave them alone. The probability of another thread asking why you can’t get a firm pedal after the “upgrades” is high here. If the switch is bad then use a Harley pressure switch. You could also do what I did and add a relay in addition to the H-D switch, I wired it so that the switch now controls the relay’s ground and that takes all of the load off of the switch contacts and the high amp load is handled by the relay contacts instead.
This! If the switch is bad then use a Harley pressure switch. You could also do what I did and add a relay in addition to the H-D switch, I wired it so that the switch now controls the relay’s ground and that takes all of the load off of the switch contacts and the high amp load is handled by the relay contacts instead.
I replaced the single pot mater on my '63 Falcon with a dual master from a late 60s Mustang and just used the later pressure type brake switch and port on that master. Worked great and never had a failure
I too, had problems until I went to a Harley hydraulic switch. It's been several years and not one problem since!
I got rid of that single piston master cylinder on my 58' and switched to an updated duel piston after a failure that was a real eye opener. I switched to a 12 volt switch electric after the pressure one started to only work when I was almost at a complete stop one night. Not hard to change over and is cheap insurance.
After my almost new Harley switch went bad I gave up and went with a mechanical brake light switch. Never had a problem with the brake lights after that.
That brake light switch is just a 47/59 Chevy truck brake light switch that can be found at any parts house worth it's salt. Standard SLS40 is a common parts number.
Just a word of warning, Speedway sells the same switch but I went through 2 of them . The would stay on all the time after about 4 months. I ended getting some nos ones off of ebay I'm still on my first one after a year. I can't speak to the rockauto one. Phil
I use these on every brake master cylinder upgrade. Ford has been using them from the later 60’s to well into the 1990’s….never had one fail.
https://www.google.com/search?q=for...ate=ive&vld=cid:2b4879c4,vid:nbNPbCCuHlM,st:0 Video of installation on a Mustang.
The older GM manual switch was also used for neutral safety and back up lights switch’s. Had a 54 Chevy with three on the same car
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