No break lights after adjusting my rear brakes

No brake lights after adjusting my rear brakes today.
It's an early Bronco 9" rearend in my Model A.
Is it a coincidene or a crappy switch thats pressure or travel distance challanged.
It's a hyd. pressure switch, Not mechanical.
Brake lights work fine when I jump the circuit.

 

i assume you got good pedal pressure after adjusting so i would be inclined to think bad switch. it is an awful coincidence.

 

Have heard nothing but bad about pressure switches. That seems to be your problem if you jump it and have lights...

 

X2 man. Terrible coincidence, but that what I'm betting on.

 

Is it a stock switch? With the brakes adjusted properly, your car may be too light for a stock switch. I had that problem with my '32. I got a Ron Francis low pressure switch, problem solved. I even bought an extra switch because I heard that they wouldn't last. 10 years and counting.

 

Pretty good pedal pressure considering I've got too much cam and marginal engine vacume but that's a discussion we can have for another day.
My wife said the brake lights worked fine yesterday when I rolled out of the driveway before doing anything to it.
It's weird that they went out after I tightened up the rear shoes.
Pedal travel is better, still stops the same, just no light now.
Odd !!!!!
I guess I'll pop the pressure switch out tonight after dinner and swap a new spare in the I've got up on the shelf then bleed the snot out of it.
See what happens after that

 

It's either a coincidence or it's been bad for a while and you just noticed it

 

Ahh.........the many puzzles of a home built crap-can.
Yes, it might have been on the way out for some time but ony went noticed this morning while making a rod run and having a buddy behind me noticing it.

 

I've got an inline switch on my 48 and had to replace it every couple of years since I have had the truck together in the current configuration. It is probably a coincidence more than being something that happened because you adjusted the brakes.
But if you caught it before getting pulled over for no brake lights or getting hit in the rear end because someone following you didn't know you were stopped or slowing down that is a good thing.

 

Have someone "stand" on the pedal as you put your OHM meter across the two terminals on the switch. You should have your answer directly. Meter moves= GOOD SWITCH. I'll bet the meter does NOT move. DD

 

The brake pressure switch is usually located in the "front brake" curcuit. If the adjustment eliminated enough slop in the system that the master cylinder "hydraulic stops" on the rear brake system before enough pressure develops in the front brake system to activate the switch, then this can happen.

Either loosen up some on the rear brakes or bleed the fronts and see if it goes away.

 

I have found the LEVER type brake light switch to be more reliable and less trouble prone. Lots of the late 50's early 60 GM vehicles have them stock. PLUS ... if one goes bad ... you do not have to mess with the master cylinder/brake fluid issue.

EASILY ADAPTED also ...

 

x 2 x 2 x 2

 

I can't imagine how that would happen. Unless the car has separate master cylinders for front and rear brakes. Dual cylinders are set up with the pistons in series, one pushes the other, so pressure is the same in both sides.

I'm assuming the switch is not after a proportioning valve...

 

No doubt, heres the one I use, been in for 10 years or so





http://www.speedwaymotors.com/Universal-Mechanical-Brake-Light-Switch,1972.html