Pontiac Problems? Ask a Mechanic for Answers ASAP
Did you pull the brake pads and caliper off the carrier, and check to see if the caliper slides slide ok, and the pads are not binding in the carrier? Do you live in a rust belt state?
I meant if you lived in a state that uses salt in the winter. Do you have a way of lifting the vehicle to see if wheels rotate (even if just putting it on jack stands in the front end) and a friend to help you?
I would lift the front end, see if both wheels spin freely by hand, and then have someone operate the brakes gradually, and see if one grabs before the other.
It's also possible that the ABS pump has a bleed program that needs to be run to fully purge/bleed the brake circuits.
So when that wheel locks up, the ABS does not pulse it at all? DO you have any way to read faults? I'm wondering if you have an issue with a wheel speed sensor.