I have to agree with Quicklook2 and andym. What may work for mistercmk, doesn't hold true for all. I was raised the same on "If it ain't broke, don't fix it" saying, but if you talking about something as neglible as bulbs, cool, but when you get into the ability to stop a 2 or 3-ton workhorse, I would spend the extra money and get a new caliper for the other side. I like the ability to stop as much as I like something to be done right the first time, not wait until it's 30 below, piston either hangs, sticks, or blows the seal dumping fluid and only one side is stopping you. It's a lot cheaper than to call a tow truck, or a mechanic for an appointment. I guess I'm just a "pairs" kind of a guy.

 

Its a no brainer! Replace them both. As cheap as they are a person is taking a huge risk ( with brakes ) not replacing them both. Wheel cylinders too. ! old ones are weaker and wont hold the same pressure. You may be doing the other on in just a few weeks.