Where's the Brake light switch?

[Terrapin Flyer]

The dash brake light has been on since I've owned my '83 K5 (a couple weeks) and I'm guessing that there's a switch issue at the parking brake pedal, but I can't find it. Where is the switch located exactly? I looked through the POS Chilton manual that came with the truck to no avail. Gotta get a real manual.

Thanks in advance...

 

[dyeager535]

It's way up behind the pedal assembly, behind where it pivots, sort of up near the firewall, IIRC. White plastic, with one wire going to it?

Stand on your head, you'll see it lol. Bring a flashlight.

make sure it isn't the proportioning valve on the front frame crossmember. Disconnect the single wire plug to it, if the light goes out, the brake pedal isn't your problem. Only two components on that circuit.

 

[BulldogK5]

Mine was the switch on the brake pedal itself. Like stated, look at the top of the pedal there is a little piston type of switch that has probably lost the power feed. Give it a constant 12V and it should go away. A friend of mine has run into this problem on several different GM's of this vintage with the same problem.

 

[Terrapin Flyer]

It's the proportioning valve

I have no rear brakes. I'm embarassed to admit that the rear brake fluid was empty. I didn't check it when I bought it because the seller told me he just just put in a new master cylinder. It is obviously new, but I should have checked the fluid anyway when I noticed the brake light on in the dash.

I can't get the prop. valve to reset. I read about a switch on the left end, but under the rubber boot it looks more like a bleed valve of some sort, and will not depress. I guess I got my work cut out for me.

 

[dyeager535]

Ask grim reaper(?) I think he's the one that did the whole rear-disk/proportioning valve write up, can probably answer how to reset that thing.

All I've heard as well is to depress something, but it's never caused me a problem when I have done brakes, so never had to check the setup out.

 

[Jason4x4]

usually you will need to find out why the rear brakes don't work, Probably a bad wheel cylinder, then bleed them, and during bleeding, the valve will usually reset itself.

 

[badger red]

If you can't get the switch to reset, bleed the lines at the master cylinder. Have a buddy pump the brake pedal/hold pedal/crack tube nut at master cylinder to release fluid/tighten tube nut/repeat. I've had to do this several times on different trucks--1/2, 3/4 to get the light to go out. Hope this helps.

Jeff

 

[Terrapin Flyer]

Thanks Badger red, I'l give that a try. Yesterday I put in new wheel cylinders (one was a leaker) and bled the rear lines, but the prop. valve still didn't reset. I'll try your trick, and if it doesn't work a new MC will be my next step. I'm assuming you're refering to the rear nut at the MC since that's where I did the work.

By the way this thread should actually be combined with my other thread (Highway Death Machine) since they turned out to be the same problem. Sometimes the obvious will b*tch slap me and I still don't get it.

 

[Muddytazz]

You could take it to a shop and spend $20 to have the whole system (pressure) power bled

 

[Terrapin Flyer]

Conquered

Today I bled the MC, bled all four wheels (ran like a quart of fluid through them), tapped on the prop. valve with a hammer to loosen it up, and shazzam. The brake light went out and the rear brakes work now.

It's amazing how much better she stops when all four wheels grab. When that red light on the dash dimmed I just wanted to give her a great big reacharound.

 

[badger red]

Glad to hear you got it under control. Like Muddytaz said, powerbleed for $20 is another option--should have mentioned that after my suggestion.

Jeff

 

[Goose]

Congrats!