Brake Lock up

[lotorc]

Hi was talking to wife today and she was driving our truck (I work out of the country) a 2002 7.3lt superduty crew and she was saying that yesterday while braking that they locked on (and of course she didn't notice until the smoke started and the truck would bearly move).
She stop and turned the truck off and hoped out and after about 2-3 minutes she heard them release and carried on driving home with not worries.
All four locked on.( Not locked up but on)
What would cause this. Can anyone help.
I tolded her not to drive the truck till I can get it checked out.

Thanks Lotorc

[Type 2 Sniffer]

Did you see the ABS light go on? If it did, run the code. Mine did the same thing and it turned out to be the rear speed sensor. I think it was $18 and an easy do-it-yerselfer. Hope this is what it is as I was in and out in under 1/2 hour. The drivers' side front went out later and that one, ford wanted about $200 for. Good luck.

[lotorc]

The ABS light has come on.
And I will be checking the sensor.
Thanks again.