Brake light switch replacement

Hi Austin.  I don't know, but I've been told that the brake light switch is on the brake master cyllinder & there is often a redundant one there, which means if you move the connector from one to the other, you may be back up and running quickly.  Probably requires removing the LF wheel to get access.

If you DO have to put in a new one be aware that you will likely introduce a little air into the system.  I have been lucky on past cars to avoid having to bleed the system by doing the following:

1. Pour a little brake fluid into the switch.  If you see a small bubble trapped in there you can pop it by CAREFULLY poking it with a pin.
2. Unscrew the old switch, making sure that you have a towel below it as some fluid is likely to run out.
3. Pour a little fluid into the opening from which you removed the switch and then quickly insert the new one, screwing it in.  This will be a little messy.
4. Check it out to see if everything works.
5. Call me an idiot if it doesn't.  Some people don't even wait for step 4.

If you do what Lane suggests you may luck out and won't need to bleed the brakes.  

 

If, after the installation your brake pedal is soft, you'll need to bleed your brake system to get the positive pedal back.

 

Not a big deal, just annoying.  And plan on doing this every couple of years or so - That's how long these hydraulic brake light switches seem to be lasting these days.

I went through a couple of the master cylinder switch units before it was decided that something more reliable was needed.  I now have a regular mechanical switch that is located near and activated by the brake pedal.  The problem now is the cheap Chinese parts that fail on a regular basis.  In its current iteration, I'm using an Intermotor S6112 Switch/Commutateur Interruptor.  Long name for a brake light switch, but this one seems to have a little staying power.  Here's hoping.  

I went that route, too, but I went to NAPA and got a mechanical brake switch for a 1937 - 1956 Chevy pickup truck (yes, they still carry them - they're pretty popular, I guess).  

 

It has an arm that I bent to ride on the brake pedal arm so it closes the contacts after the pedal starts to move.  Been working great for several years now.

I have been planning to follow Gordon's lead on the mechanical switch but haven't yet gotten around to it.  The hydraulic one seems to require a fair amount of pressure so I doesn't come on as quickly as I would like.

Charlie Padula, at Charlie's Rod Shop here in town, tells me that Chevy (actually, most of GM) used that switch on just about everything, Pickups, Bel Aires, you name it, from the mid 1930's to the mid 1950's so they're available just about everywhere.

 

They look like this:

 

 

Screw the bracket to the floor so that the arm swings correctly, put a small bend at the tip of the lever to ride nicely on the brake pedal arm, hook up the wires and "Go to Town"!

 

I added a small rubber boot (can't remember where I got it from) to cover the wires and I used 90 degree connectors on the wires to make everything neat.

 

Maybe I should make up easy-to-install rework kits!

Thank you boys. Gotta luv SOG!

Lane, the switches vary in sensitivity, just like the oil pressure idiot light switches. Swap it out, you may get a more sensitive one.

 

You really shouldn't have to bleed at all if you swap the switch like Lane and Gordon said.