VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 40 brake light switch

I noticed I've got to really push the brake pedal down way to hard in order to activate the brake light switch. I'm sure this isn't the way it's supposed to work-or is it? The switch is basically new but about 3 years old. The complete brake system has been replaced with correct parts with no modification.

I know this switch is hydraulically activated and doesn't operate like the modern switches.
I just need to know if I need to replace it or live with it.

Thanks!
Curt

The contACTS INSIDE THE SWITCH ARE GOING BAD. rEPLACE THE SWITCH. I HAD TO REPLACE THE SWITCH EVERY TWO YEARS ON MY '39 DUE TO USING dOT 5 SILICONE BRAKE FLUIS. I FINALLY MOUNTED A LEVER TYPE SWITCH LIKE A 1942 AND UP USED.

Thank you Chevgene.
I'll replace the switch.

Curt

I agree with this. Same experience and solution.

dick

I got tired of constantly replacing mine so I changed to a later model mechanical switch.

I changed my '37 over to DOT5 brake fluid after I bought the car in 1992. The original brake switch is still in it and works with no problem. The new, imported switches are junk !

The new from NAPA hydraulic brake light switch I installed in my '37 Master coupe performs similar to what Curt describes. It takes more pedal movement and pressure to make the brake lights come on than I would like.

The key is the design pressure required to make the switch work. Ford used hydraulic brake light switches at least into the mid 60's. My understanding is that those systems operated at a higher pressure system so the higher pressure switch would come on very soon in the pedal travel. Most of the replacement switches you buy today are for the Ford system. Unless you can find a NOS Chevy switch you will probably get the higher pressure switch.

I drive my car around town quite a bit and in traffic so I would like to have the brake lights come on sooner. My plan is to do what Gene did and add a mechanical switch to the system. I will wire it in parallel to the hydraulic switch so if for some reason it fails I will still have brake lights.

This is the type of switch I changed to. I mounted it to the firewall to be actuated by the brake lever being pressed. I ran jumper wires to the OEM connectors at the pressure switch. My brake lights now come on simply by touching the pedal.

Hi Tiny,

That's an interesting point made by Rusty and makes sense to me.

I just got a replacement switch from chevs of the 40's (made in Mexico). If it does the same thing as the other (I'm betting it will), I'll certainly consider the mechanically activated switch you used. Where did you purchase that one?

Thanks,
Curt

Local parts store.

There are a few different versions of that switch. The most common version fit 1942-1950 cars and 1942-1956 trucks.

After 3 aftermarket switches out of order again after at least one year I had enough of that miserable *made in indonesia* quality and did construct a selfmade mechanical switch based on common today sold electronic switches and pressed by the moving brake pedal and now since two years I am sure to have a working brake light when leaving the underground garage for a ride. Aftermarket parts are nice, but sometimes they are not worth the price you have to pay for it...

STefan from, germany