Jack it up and see if the front wheels spin freely. I had an old truck that one brake had collapsed internally. It had failed in such a way that the fluid could only flow one way. It got so bad that the wheel was extremely hot. I changed the rubber brake hose and that fixed it. So I bled out all the fluid and also changed the the other side hose. Was OK after that. It also could be an alignment problem. Check for loose ball joints etc.