Having been a proud owner of a Blackbird for 14 years (1997 model, carburettor engine, old school!!) I recently changed to a Yamaha XSR 900. I took off the brakes to give them a clean, but I noticed the manual says to open the bleed valve, on ABS models, if pushing the pistons back into the calipers to let the fluid out. On my Blackbird I just pushed them back in and the fluid went back up the tubes into the reservoir. I didn't have far to push them as I wasn't putting new pads on, but I've since read that on the XSR this can mess with the ABS system. So do I need to let some fluid out via bleed nipple in this way? Risking letting some air creep back in to the system. Or is it okay to push the pistons back in if changing the pads, meaning they will need to be pushed right back in to make way for the new pads.