Brakes locking up

Has anyone ever experienced brakes locking up while driving 50 mph

Not me, and I hope I never do.

Your car has anti-lock brakes. They should never lock up, even if you try to make them.

Can you give us a few details, please. Maybe more than a few.

Are you saying all four wheels locked and your car skidded to a stop from 50 mph?

Yes. I have also experienced brakes locking up at 75 mph. Could you be more specific about what your concern is so we can help you better? Also provide year, mileage, ABS or no ABS, and other pertinent information about your vehicle.

I was driving my 2004 V070 on a divided road in traffic at about 50 mph, all of a sudden the car tried to come to a screeching halt. It felt like all 4 tires were flat, or that I had run over a body. I was able to keep accelerating until I pulled into a median break area. It was a frighting experience. I got out and looked at the tires and they were fine. There were marks on the road where the front tire had skidded, not sure about the others there was too much traffice.
I did not know what to do, since I was between the roads I knew I had to get out and off the road, so I backup, there was allot of screeching but I kept driving and was able to make it to my home, with breaks and in control about 50 miles away, safely. I have an appointment at my local shop this morning, but it is also a mystery to them so if any one has an answer it would be appreciated. It felt like someone had reached over and pulled on the emergency break. Or something got caught in a wheel but there was nothing in the road.
I can not trust a car that does this and my have to replace it.

The mileage is 90K
Joann

Rather than the brakes, I think that a bad wheel bearing may have caused a front wheel to lock.

However, because the original post and the later update are written…not very informatively…that is just a guess.
From those posts, I am having a hard time figuring out whether just one wheel locked up, or if it was both front wheels, and it is not clear whether the “lock-up” continued after the initial incident.

Were you using the brakes when they locked up? Or were you using the gas and/or cruise control?

Does it have VSA (stability assist)? We have a fleet of Escapes at work that have poorly-implemented VSA. Sometimes it will incorrectly decide that you’re in trouble and slam on the brakes. In the Ford’s case, I think it’s a design flaw because all 8 of ours do it. In your case, it could be a module that’s getting ready to die.

But VDC could be just as right - your wheel could have locked up due to a failed bearing.

Yes, stability control is the only thing I can think of that has the ability to apply the brakes without driver intervention, although I don’t think it can “lock them up.”

Now that vehicle stability control is required on new cars I wonder how often this sort of thing will start happening? Especially as vehicles with this feature age.

The screeching, however, and the fact that the brakes worked fine afterward, could indicate something else, such as a bearing.

Yes it could.

I will tell you from personal experience with the 8 Escapes, though, that VSA can absolutely lock up the brakes. When it freaks out in the Escapes, the brakes lock, the tires squeal, and it stays that way until the car is almost stopped.

Needless to say I try to avoid driving the damn things whenever possible.

Can’t say I blame you. I didn’t know VSA was that powerful. My cars are not new enough to have it. Thanks for the information.

Sounds like another good reason to wear a seat belt.

VSC, AdvanceTrac, and whatever else it is called all use the ABS unit to apply the brakes, so physically (at least) they can certainly apply full brake pressure to any and all wheels. It should never override the ABS function and lock a wheel, but apparently when it malfunctions it does (no experience with this problem myself).
Please note that some cruise control systems can also ask the ABS unit to apply the brakes.

When I first read about these stability control systems using brake application on individual wheels to “stabilize” vehicles my biggest concern was that we’d begin to see these types of malfunction manifestations. I hoped I was wrong. Apparently I was not. I worry that as these cars age we’ll see more of these. I hope I’m wrong.

To the OP I strongly recommend that in addition to getting the problem corrected you write a letter to the National Highway Traffic Safety Association. it’s important that agencies such as this be made aware of dangerous situations resultant from these system designs.

I took the car to my mechanic, the diagnosis is that the emergency brake disintegrated in the 90K miles and broke apart jamming the brake on. I do not have regular inspection done of the whole car as we did in the past. Perhaps this would have been found, maybe, not.

It probably would not have. Many cars today use small shoes and small drums cast into the center of the discs to accomplish parking brakes. Inspection of these requires removal of the discs, and that’s not a mormal part of annual inspections.

I was driving my 2005 Dodge Ram @ a speed of approx 25 when suddenly felt as though my brakes locked up momentarily? Not sure what that was about and it did not do it again???