Pulling to one side while braking
 

88 xj 4.0 auto.
While applying the brakes I get a pretty good pull to the drivers side front wheel. In the rain It even locks up on occasion. It doesnt lock up right off, but with a little harder pressure, it eventually locks up. (only in the rain. Not on dry surfaces)
Ive checked the levels, all seem fine. brakes are fairly new as well. No grinding or vibration.
Any help or suggestions?

frozen caliper maybe? I get a slight drag on one side *drivers side* when braking.

either a sticking caliper piston or your slide pins are gunked up causing the caliper to "stick"

so basically take it apart and lube.. Napa auto sells rebuild kits cheap also.

x2

there easy to rebuild and cheap to do.
mine used to do the same, so i just got a kit and did it in about a hour or so [not rushing].

I normally pop the slide pins out and put a fine layer of anti seeze on them.

^^^ I always do that when swapping pads.

should I clean it up a little with some brake cleaner first? Before the anti seez.

I would wipe it down with a rag then grease it.

check your bearings also theyre a cause of memory steer

i had a truck that did that and the cause was a bad tie rod end , seems kinda weird but if its got play in it when you hit the brake it could tighten up at the wrong at angle and cause a pull

Could also indicate you need your rotors turned, or need to be replaced if it is no longer flat.

Everyone has said good answers..

Uneven brake wear can cause this, if your passanger is warped or something and wore your passanger brakes down further than driver, that would explain the locking and hard pulling.

Mine pulls passanger because of the bad steering knuckle (where the tie rod goes) But doesnt cause any type of wheel lockup. Basically the same problem as having a bad tie rod end.