Another thing you might want to check is the brake pads. Over the last couple years a lot of the brake pads I've installed for other's has a common issue. They don't float on the slides like they should. The pads hang up (too tight) on the slides. Some just have a excess amount of paint (powder) on the pads and others need to be cleaned up with a file. It seems more common with parts from"rock auto" and some of the cheaper pads from local stores. I always prep the spindle with a wire wheel to remove rust and build up before installing the pads hardware, so I know that isn't the issue. Even with disk brake lubricant it doesn't always solve the problem. Just another thing to look at to help solve your issue.

 

I had this problem on my grand prix where the front brakes were similiar set up. Also had problems on my monte with it. There are several stupid things i found that are not really any mechs fault.
1. Those rubber bushing slide pins. Like the other mechs said above over lube can cause a suction type issue where they wont retract when brake released. I also noticed some lubes swell these rubber bushings. They were jammed in my monte after sitting a winter. Had to air hammer the pins out and pick out the rubber in the caliper bore what a pita. I bought a new set of pins and just used 2 straight pins with no rubber bushing. Some mech online said he did the same for years with no issues. I can vouch for no notices abnormalities for deleting them. Did so on both my cars.
2. Brake pads. These are getting worse. If you put a new pad with new abutment clips called above, make sure you clean where they go so they sit flat and put a small amount of lube on the pad where it contacts. What i have noticed is the pads are coming out of specs fittment wise on the car from several brands. Check to see if the pads move smoothly once installed prior to attaching caliper. I have had to file and sand several pads were they contact the clips cause you almost have to jam them in. Keep in mind the filing removes the coating and they rust there quicker so sometimes you need a little extra blend to account for rust down the road or they jam from that.
3. I added drag reduction clips from raybestos from rock auto. These are like mini springs that push the pads back out. They can be a pain to install, but it def shows whether your pads move smoothly and is supposed to keep the pads from resting against the rotors while driving. Newer cars have these incorporated into the clips.

Outside of these stupid things i call em. Bad caliper or caliper hose. You can tell when you c clamp close them whether one is harder to close than other during pad change. You can buy special tooling. I had same issue with my grand prix and bought load cell readers to show actual brake pressure to rule out hoses and calipers that i already changed. For the pulling that could be a dragging brake, misalignment, tires, the road itself and so on so forth. I also had excessive rust on the wheel hubs, rotors, and wheels were they all meet up. This caused vibration and may have played a role in burning through the pads as uneven surfaces mean uneven travel and if the pad doesnt contact flat and the rotor wobbles it will eat the pad faster.

I have yet to conquer why the inner pads on all my cars wear faster than the outers aside from rotating them and saving half pads.

All i can guess....

 

When I said that I use anti seize, I put that on the threads of my pins so that I can break them loose when I change the pads. I have never put any grease or lubricant on the part that the brake pads slides on.

 

Thats a bad idea in my opinion. My buddy whose a big car buff said gms were notorious for the caliper bracket and pins backing out. I put a little red loctite on mine. Its a high vibration area. In my opinion at least. I put them on the wheel studs before even a small amount and the lugs would back off over time. Rather have a wheel difficult coming off rather than falling off. From a person who had a wheel fall off for completely different reasons.