Help with reoccurring brake light

[Dan Hunter]

I was operating the truck on frozen precipitation and the anti-lock brakes functioned. After that though the brakes seemed spongy. Since then, when I apply the brakes the parking brake light comes on if I push hard on the pedal. Consistently, if I shut the truck off and restart it the light goes out and I can use the brakes lightly but it comes on again shortly after a firm application of brake pressure. The brake level is above the min level index but is lower than I'd expect but honestly it isn't something I look at.

Is there a low level sensor in the reservoir that's going off as the level drops as I move fluid to the calipers? Are the brakes spongy because I've introduced air into the lines? Does any of this make sense? It's just another thing I've never experienced.

I continue to try to think of this truck as giving me opportunities to learn rather than reasons for developing migraines.

 

[NVW]

With the level being low I would suspect a leak somewhere.

 

[Dan Hunter]

Did some reading on the 'net. I've put pads on the front but never on the rear. I'm thinking at 155000 miles, it might be time to do 'em all and flush the lines. I'm thinking maybe it's taking so much travel to actuate the pads that it could be draining the reservoir.

 

[ak diesel driver]

maybe the ABS cycling unlodged an air bubble and pushed the proportioning valve off to one side

 

[Big T]

Did some reading on the 'net. I've put pads on the front but never on the rear. I'm thinking at 155000 miles, it might be time to do 'em all and flush the lines. I'm thinking maybe it's taking so much travel to actuate the pads that it could be draining the reservoir.

Yes the first thing you should do is eliminate the rear brakes as a contributory issue. The recommended shoes are the AC Delco Dura Stops. Make sure they are adjusted properly.

 

[Dan Hunter]

Got a chance to look at it all. The rotors are worn below turning, the calipers stick and look horrible. They're getting replaced along with new brake lines. Strangely, the rear end - that's never seen any attention - is fine.

 

[Dan Hunter]

Fresh rotors, calipers, pads, brake lines and fluid has the ugly old gal back pounding out miles on the cheap. Sadly, it sounds like the ranch is frozen over still with a massive snowfall. Good news for the trees and pond; bad news for me. I think I'll build a gong for the shooting range and finish the prep for my ballast barrel for something to do.