Wow...this scared the cr@p out of me...Advice?

Driving in town in my 1995 Chevy K1500. Without warning the front left wheel locked up momentarily. I was not braking at the time.

I was able to reproduce the effect again. It seemed not to repeat if I kept slight pressure on the brake.

The pad and disc appear in good shape. The brake fluid was horrendous. Now with fresh fluid, I am still nervous about driving it. Does anyone have any theory how the condition of the fluid might have triggered this? If not, does anyone have a theory. As an aside, I’ve had some strange electrical problems recently…headlights working erratically. etc…

My best guess is that the flexible brake lines are severely deteriorated on the inside, and that the one for the left front brake is collapsing intermittently and locking the brake on that wheel. If I am correct, you need to replace ALL of the flexible brake lines right away, before you cause a serious accident.

And, now you know one of the reasons why your brake fluid should be changed every 3 years or so.

The rubber brake line to the left front wheel is the most likely culprit as VDCdriver states. This is a very common problem. You need to heed his advice and replace the rubber brake lines at all 4 corners to be on the safe side.

The rubber brake lines like they said. Replace the two on the front and the one at the rear axel.
I just went thru problems my lights on my 97 K1500 Chevy. I had headlights, no taillights or dash lights. I checked the fuse it was bad. Traced it to a bad taillight circuit board. Replace both of them. Good for about a month. Fuse bad again. I went thru all of the wiring and switch. Gave up and made my owen wire circuit for the tail lights and dash lights. The wiring in your 95 is the same as my 97. The plugs for the head lights are different. I would first check the grounds and the switch. Some of the 95’s have the same dash panel as the 96-98. If you have that dash panel the problem could be in the circuit board of the dash. I think that was were my problem was. Not sure. Like I said I gave up and got out some relays, wire,inline fuse and the soldering gun. No more problem.

OK, will replace the rubber brake lines immediately. Can someone explain exactly how VCDdriver’s scenario works? I get that the line is deteriorated. Does the line collapse momentarily? And how does the collapse activate the brake?

“It seemed not to repeat if I kept slight pressure on the brake…The brake fluid was horrendous.”

Any pressure on the brake pedal is sending fluid under pressure to the caliper/wheel cylinders. Sometimes the breakdown of the interior of the lines acts like a check valve - it will let pressure through but won’t let it release.

Can you elaborate on “horrendous” with regard to the fluid?

When you replace the lines make sure that you check out the calipers, especially the slides. The caliper needs to be able to float in & out as you brake/release.

Something like that would scare me too. I’d be inclined to change the brake lines throughout the vehicle and maybe even go so far as changing the caliper and pads on this wheel . . . and double-flush the system. Good time to go over wheel bearings too. My theory? The caliper stuck because your fluid absorbed water and was really dirty . . . . and caused the caliper to malfunction. Can you clean-out the rust and gunk by changing the fluid? Maybe, thus my suggestion to replace the caliper. That “left front wheel locked-up momentarily” scenario can really ruin your (and someone else) day. Good luck! Rocketman

cigroller: the fluid was black and seemed to have a “sheen” on it that I took to be water. To the best of my recollection (nearly certain) I was not braking at the time the brake locked up. The rest of the hardware appears in very good shape. You’ve made me remember another fact…I had not driven the truck for several weeks. When I first drove it the brakes felt soft. The peddle traveled far but breaking was good. Before I got to the end of the driveway, they firmed up. The route I drove had a two mile downhill right before the incident.

I was having trouble reconciling hose failure with with the scenario you described until you mentioned the 2 mile downhill grade. My vote is water boiling in the caliper. You solved that problem when you replaced the fluid, but it still would not hurt to replace the hoses on a 15 year old vehicle.

Your last post suggests that air in the caliper may have been heated on the downhill and expanded, in effect applying the brake.

The vehicle is 16 years old. You clearly travel in a hilly area. Brakes are the single most critical safety item on the car, the single most deadly if they fail…especially on a hill. If it were me, I’d change both fromt calipers and the flexable hoses, and flush the system out well with fresh fluid. Examine the hard lines for corrosion while you’re under the vehicle, just in case.