Odd electrical question time. I got in the truck to run some errands, took off the parking brake, and the light stayed on. A couple minutes later, it went off. A minute or after that, back on. And so on as drove along.

I didn't notice any drag to indicate that it hadn't actually released, so it's gotta be the electrical bits.

What am I looking for as far as a sensor it switch (since I'd rather look there than trace the wires looking for a short)? And, where would it be (I'm expecting it to be near/attached to the release)?

 

Check the level in the brake fluid reservoir.

Low fluid can light the light. If the low fluid sloshes the light may go on and off.

 

Could low fluid also cause a sound which I can only describe as kind of like holding a wire brush against a spinning rusty disc?

 

No, but worn brake pads, or shoes might.

 

Fluid level at just the right low level could trip the brake light. Also make sure your parking brake is set all the way in. The sensor for it is at the very bottom of the rod and has a little tab that pushes in on the sensor.

That wire brush noise? Do you have a header on? A header will have a similar noise.

 

Release was all the way in. Engine is stock. The fluid is above the minimum, but getting close (it's right around the seam - maybe 1/8 to 1/4 inch above the minimum line). I'll be picking some up tonight or tomorrow. Is the current level likely to be problematic?

 

My 91 doesn't like it when the brake fluid is near the 1/2 way point. It will start intermittently tripping the brake light as the fluid shifts over dips and bumps.

2wd truck, stock height front and rear, tires are all the same size.

 

Finally got a chance to drive after adding fluid (had a bit longer trip out of state than planned).

That seems to have fixed the issue. I need to clean the reservoir and add a hand-written label for 'Low'.

Thanks again, everyone.

 

Great to hear you got it fixed.