buy a new disk brake
Quite possibly an ABS* failure. Have that looked at. *ABS - Anti-Lock Braking System.
Lots of them, disk clean up, disk fragmentation, that moves the data up front for faster access, check disk for error's, blow out dust from inside
If you have lock outs or free spinning front hubs, you turn the center of each front hub to lock them in. If you don't have lock outs, they lock in when you put it in four wheel drive. To unlock them, take it out of four wheel and slowly back up 3 to 5 feet.
Anti-lock breaks is safety devise. How it works is when your going a good spead down the road and you jam on the breaks. It will push the break petal back up. It wants you to pump the breaks so you wont skid. I took mine out I don't like it.
is it disk up front drums in back
When you hit the bump and you have the brakes applied, the tire will lock up when the tire is air-born for a moment.
yeah sometimes my breaks lock up too when I try to stop too fast, perhaps you should break sooner and this will help
Depending on the vehicle I had one lock up because of a bad brake caliper. If you have four wheel drive it could be your front diff locking up I would start by looking at the calipers.
if back brakes are drum i would think they are worn out not allowing pistons in wheel cylanders to return. also could be valve in master cylander.altho that would cause all brakes to lock up. if disk brakes your calipers need overhauling or replacing
The actuator is located on the front axle.
it could be a few things. Could have bad berrings, breaks could be sticking.. I would take it to someone and have it checked. Don't want a stuck caliper (spelling) and your tire lock up.