The Ford Barn

randy993 · 06-30-2025, 12:53 PM

Hello all
Looks like I need to replace my 12v brake light switch on my master cylinder. Any recommendations? Thanks

19Fordy · 06-30-2025, 01:03 PM

I use the Harley Davidson motorcycle brake light switch.
Read thru this material:
https://www.fordbarn.com/forum/searc...rchid=45299710

OLDMANKOHOUT · 06-30-2025, 02:43 PM

Not for use with silcone brake fluid.

Standard pressure and low pressure switch

https://sacramento-vintage-ford.odoo...r-cylinder-938

19Fordy · 06-30-2025, 02:54 PM

Interesting, I use that switch with silicone brake fluid with no problems.

randy993 · 06-30-2025, 02:56 PM

I couldn’t get your link to open

randy993 · 06-30-2025, 03:03 PM

Sponsored Links (Register now to hide all advertisements)

I’m going by Napa tomorrow and see if they have anything. My local napa and oreilly used to carry some older stuff but now if it’s not in the computer they don’t know what it is.

Kube · 06-30-2025, 03:42 PM

Quote:

Originally Posted by randy993

I’m going by Napa tomorrow and see if they have anything. My local napa and oreilly used to carry some older stuff but now if it’s not in the computer they don’t know what it is.

I bought three in a row at Napa. All three were defective. Drove me near the brink of insanity. Three in a row? I thought that not possible. It is and it was.
Then bought two of these (below) via Amazon. Both worked and continue to work perfectly.

Hydraulic Rear Brake Light Switch DS-272191 Compatible with Harley Davidson Sportster Softail Touring Dyna Super Electra Glide Road King FXR Deluxe Fat Boy Low Rider Heritage 72023-51A

Flathead Fever · 06-30-2025, 04:31 PM

If I remember correctly there is a low pressure and a regular pressure switch that look identical. Seems like there were some peoples brake lights staying on with the low-pressure switch. I'm guessing the residual pressure valve in the master cylinder that holds a little pressure in the system when the car is not in use was just enough pressure to activate the lights. So, if your given a choice of pressures I'd go with the higher pressure of the two sensors. My sister has a '64 1/2 Mustang that still uses a switch that looks just like these, it screws into the master cylinder and works off of hydraulic pressure. In 1965 they changed it to one that mounts on the brake pedal under the dash so I'm guessing '64 was the last year for the hydraulic operated brake light switch.

I've heard of people using the Harley brake light switches, but I've never tried one.

06-30-2025, 12:53 PM	#1
randy993 Senior Member Join Date: Mar 2018 Location: King NC Posts: 112	Replacement brake light switch Hello all Looks like I need to replace my 12v brake light switch on my master cylinder. Any recommendations? Thanks

06-30-2025, 01:03 PM	#2
19Fordy Senior Member Join Date: May 2010 Location: Coral Springs FL Posts: 11,603	Re: Replacement brake light switch I use the Harley Davidson motorcycle brake light switch. Read thru this material: https://www.fordbarn.com/forum/searc...rchid=45299710

06-30-2025, 02:54 PM	#4
19Fordy Senior Member Join Date: May 2010 Location: Coral Springs FL Posts: 11,603	Re: Replacement brake light switch Interesting, I use that switch with silicone brake fluid with no problems.

06-30-2025, 02:56 PM	#5
randy993 Senior Member Join Date: Mar 2018 Location: King NC Posts: 112	Re: Replacement brake light switch I couldn’t get your link to open

06-30-2025, 03:03 PM	#6
randy993 Senior Member Join Date: Mar 2018 Location: King NC Posts: 112	Re: Replacement brake light switch Sponsored Links (Register now to hide all advertisements) I’m going by Napa tomorrow and see if they have anything. My local napa and oreilly used to carry some older stuff but now if it’s not in the computer they don’t know what it is.

06-30-2025, 04:31 PM	#8
Flathead Fever Senior Member Join Date: May 2010 Location: Yucaipa, CA Posts: 1,358	Re: Replacement brake light switch If I remember correctly there is a low pressure and a regular pressure switch that look identical. Seems like there were some peoples brake lights staying on with the low-pressure switch. I'm guessing the residual pressure valve in the master cylinder that holds a little pressure in the system when the car is not in use was just enough pressure to activate the lights. So, if your given a choice of pressures I'd go with the higher pressure of the two sensors. My sister has a '64 1/2 Mustang that still uses a switch that looks just like these, it screws into the master cylinder and works off of hydraulic pressure. In 1965 they changed it to one that mounts on the brake pedal under the dash so I'm guessing '64 was the last year for the hydraulic operated brake light switch. I've heard of people using the Harley brake light switches, but I've never tried one.