If the front brake caliper is sticking, the disc may be uneven. Brakes that are left to scrape on the disc for a long time before they are changed will damage the disc enough to cause sticking or slipping.
Defective caliper, restricted hose, caliper sliders sticking, contaminated brake fluid (probably not contaminated if only 1 front caliper).
The caliper might be sticking
brake caliper is sticking due to faulty caliper or rubber brake hose.
two possible causes......it could mean you have a bad brake hose or a sticking caliper
STICKING BRAKE CALIPER
sounds like your brake caliper is sticking. This would cause the pads to be in constant contact with the rotor.
Your brakes are sticking could be either the brake caliper or the hose going to the caliper
The main cause of uneven wearing brake shoes is a sticking or stuck caliper. Check to see if the caliper is releasing properly all the time.
Normally a front brake issue, could be an alignment, suspension or tire issue. Check that all suspension parts are in good condition and all connections are tight and that there's no obvious misalignment or disproportionate wear of the front tires. Next, check that front left caliper is not sticking closed and that front right caliper is not sticking open. If calipers are working, try replacing the brake hoses to the calipers, normally the opposite side to the direction it's pulling will be collapsed causing the 'offside' caliper to not close.
because the brake caliper is sticking or rear brakes are sticking
two bolts in the steering knuckle and the brake line are all that attach to the brake caliper