I had the wheels off when bleeding the brakes, and noticed that the caliper on the drivers side rear wheel seemed a bit loose. I could rock it back and forth slightly, whereas the passengers side caliper I couldnt. I know that they're single-piston calipers, so they're supposed to float a little, but this seemed really severe. When driving, that wheel also makes an intermittent squeaking sound, like the brake pads sometimes rub on the disk. It would stop when gently pulling the handbrake. The noise didn't seem to be wheel bearings since there was no play in the wheel overall, just the floating portion of the caliper.

What can I do to fix this? Does this require a rebuilt caliper?

 

Well you know, brake pads are meant to contact the disk.

Sounds like the mounting bolts could be loose. Try tightening them up, there are 2 of them that hold the caliper to the disk.

I did a brake job yesterday and my calipers didn't have any play.

 

I know that they're meant to hit the disk when you apply the brakes, but this happens all of the time. The two mounting bolts are completely tight, and there is no play in the piece (Caliper bracket?) that those bolts are directly holding to the upright. However, between the caliper bracket and the actual caliper (the piece with the brake cylinder and that actually clamps on the pads) there is a bit of play.

 

The caliper guide pins (on the bracket) or bores (on the caliper) could be worn. The pins are easy to replace and a few dollars at the dealer. Replacing the bores would probably mean either finding a sleeve you can press in, or replacing the caliper.

With every brake job, make sure to lube the pins with silicone brake lubricant to prevent this from happening.

 

Ok, great, thanks a lot!

 

probably stuck pins. actuator rear brakes are great in theory. if maintained like aaron said by lubricating. on 80% of the cars that come in my shop the customers dont use parking brake to keep adjusted and they dont contact rotor correctly. heat will take them out if they are seized. if the bores are worn then a new saddle is not that much

 

Similar issue here, but mine was simple and obvious.
The sound on mine was pad smacking the rotor every half a second when braking and could only be heard around 5-20mph. The sound didn't go away when hand brake was applied during braking. The sound was still present when braking with the hand brake and the sound was not present during reverse, and that's reversing fast.
One of the Vspring was missing. The top one was intact. I swapped the top to the bottom while I ordered the hardware kit. The sound no longer exists.

Thanks,