if you are changing brake fluid, i thoroughly recomend that you strip down your calipers at the same time and completely remove the old fluid.

it tends to collect old fluid behind the pistons that does not get bled out easily, and that fluid will be very wet if it's been in there a long time - and that is the most important place to not have wet brake fluid as it is where it will see the most heat

a good opportunity to check the seals and piston condition, and any sliders, pins etc can be cleaned up and greased to make sure that even brake performance is achieved on both sides of the disc to get the most out of your brakes