i have a 99 explorer 300 and the front right brakes are locked up and im not sure what is wrong.any help would be appreciated.

 

I believe you have a problem with the right front caliper hanging up. I don't think it is your master because both fronts would be locking. Take off your tire and you might have to take a screw driver to pry open the caliper so that you can get it off the machine. I don't think a small stone could cause it to hang but who knows.

If you can do the brakes on your car you can do it on the quad! If not, find a friend.