help with ABS brake problems

[that09ranger]

i drive a 2009 ford ranger 2.3L rwd with front rotors and back drums, when i am driving and apply the brake sometimes my brakes will lock up amd slide and grind like my abs censor is kicking in,and my pedal shakes and vibrates. it will not happen every time but it happens often. especially while in reverse and while turning. i have had it looked at and adjusted but it still does it and my braking is slowly getting worse.

 

[pjtoledo]

front or rear locking up?

one end locking up usually means the other end is not working properly.