No one uses a used caliper. Why put on the same thing that is causing a problem? That's like finding a pair of dirty socks to wear because yours are dirty.
In the '80s it was common to rebuild calipers with every brake job because they commonly filled with crud and the pistons could not be fully retracted to fit the new pads in. If they did retract enough, the pistons would usually stick leading to more problems. Ford and Chrysler had a lot of problems related to used calipers. Only GM did not have much trouble at that time. Today professionally-rebuilt calipers are so cheap that you will not save anything by going through the work of removing an old one from another vehicle. Even if you did, it would be customary to disassemble it, clean it thoroughly, and install a rebuild kit.
The fact you already noticed there are differences between the old and old calipers tells you there will be other differences too. The flex hose may mount differently putting the rubber part in a position to rub on the tire. Almost surely the piston diameter will be different which will cause a severe brake pull. You can be sure a good lawyer or insurance investigator will find that after the other guy ran the red light and caused the crash.
Also, you need to address why the old caliper isn't sliding freely. That isn't a problem with the caliper itself. That's a hardware problem typically caused by do-it-yourselfers who don't use high-temperature brake grease where appropriate. You also have to look for rust pitting on chrome-plated slide bolts, and grooves worn into the sliding caliper mounts.
It is also customary to buy calipers in matched pairs to insure even braking. Very few professionals would risk their reputation by installing just one caliper. The brake system is one where we do not do just enough repairs to fix what's currently broken. This is one that is always gone through thoroughly to put it back to 100 percent like new condition each time it is worked on. Anything less is a compromise in safety.
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Monday, March 18th, 2013 AT 8:54 PM