How to check for sticking brake caliper on drive wheel?

There shouldn't be if you've got both wheels off the ground :-) If you turn one wheel & the other turns as well then the one you're turning is the one that's sticking. It'll also be the one that's getting hot & spraying grease round the inside of hubcap.

well, it's not quite true cars with lsd's might not rotate freely either ;) if it's questionable then why not give it a quick clean anyway? do both sides and see what happens lube the sliders, make sure the pistons going in ok, renew the brake fluid do the works

Ah yes, the differential effect Well, I did that and both sides seem to stick a bit - they'll only turn about half a turn when turned by hand. Haynes suggests one possibility is a faulty master cylinder. Any thoughts?

They seem to turn independently and no sign of any grease.

Odd, are you sure you've got a sticking brake caliper?

That is my suspicion, based on the rate at which the front brake pads are wearing. Any other possibilities?

Surface of the discs no longer smooth enough, it doesn't take much corrosion. If the calipers are sticking then they normally get pretty noticeably hot & smelly.