2003 SRW rear brake caliper question!

[Got Smoke?]

Is it normal for one piston to compress back into the caliper A LOT easier than the other? Or is this a sign of a caliper trying to hang? Replacing a faulty rear rotor on my '03 and when trying to compressing the piston's back in one goes in fairly easy, and the other EXTREMELY difficult. I ordered a replacement for one side then out of curiousity I removed the other and its the same way?:what: Is this normal or should I replace both?

 

[Joush]

did you compress the pistons one at a time or at the same?