(87 244DL non ABS) So I noticed that my rear driver's side caliper had a screwed-up boot and so I opted to just replace it. Bought a new one from O'Reilly's and put it on. The end of the brake line did have fluid dripping out when it was disconnected for the record. I put the new caliper in, and the pads back in and everything was together so I went to bleed the brakes and it was taking absolutely forever and a ton of air was coming through but the pedal felt only a little bit squishy so I put everything back and drove it a bit and it felt okay but noticeably worse than usual. When I got back I noticed that the light rust on the rotor surface had been rubbed off by the drive on all corners except that rear driver's side. There was a visible gap between the pad and rotor even with the pedal completely pushed down, the pads didn't seem to move at all. I even got a pressure bleeder and tried that but got basically the same results of a ton of air and a little bit of fluid but the brakes didn't get any better. I did read that some of that air is being pulled through the threads on the bleeder so I pulled it out, checked that it wasn't blocked up or anything, and put some lithium grease on the top of the threads to stop it as much as possible but it didn't help. I know I've got to be missing something obvious here but I just can't figure it out.