I was going to change my front brake pads, when I realized they didn't need changing (the notches were still deep, lots of pad left). Like a true scientist an idiot, while the pads were out of the caliper, I pumped the brake lever, just to see the pistons move. Cool! Now the pads won't fit back in (let alone getting the caliper back on the rotor), so to push the pistons back in and make room...ok, I'll open the brake fluid valve on the caliper, push the pistons back in while collecting the brake fluid in a clean container, and pour it back into the master cylinder. Now I have enough space to slide the pads back in, and get the caliper back on the rotor.

Victory!

Except now the wheel doesn't spin as freely. If I spin the front wheel, I get a revolution or two, but it's clear that the pads are tight on the rotor.

How do I fix this? There isn't any more brake fluid than there was before. In fact there's probably a teenie bit less. And if there was a load of air in the line, wouldn't that make the pads bite less? The lever doesn't feel spongy.

(2005 GS500)

Take the lid off the brake reservoir, then push the pistons back slowly into the caliper.

Note: its easiest to do this with the bike on the center stand, and with the steering at full lock (Left / right, cant remember, but one way keeps the reservoir more level)

Put the pads back in, reservoir lid back on. Remount caliper.

Have a beer, thank me later..

Yeah well, epalm's already got the pads in and on the rotor.

Basically, with the system together (where you are at - but do check that everything is right), pump the brake hard, then go out and ride it, exercising the front brake a good bit to try and reseat things. Some minor drag is not unusual until things settle again.

If you push the pistons back in, reassemble and pump it, you'll be right where you are now. It may be something like the whole caliper needs to adjust itself 1mm to the (left/right) and it won't do that while sitting still - it will while riding.

Air does funny things to pads.  Of course, so does bad fluid.  What does your fluid look like?  If it's black...replace.

DoD#i: I'll ride it for a bit and see if the pads settle in, thanks.

jestercinti: Fluid was changed in October, about 7000 km ago.  It's not black, more like the colour of apple juice.