I'm not convinced I've the technical confidence to do that Darsi.Assuming you unbolt the caliper and pull it away from the bike before gently applying pressure on the pedal?Do you remove the pads or can you get access to the pistons?Do you then prise the pads apart to refit?When the bike was serviced they did say the pistons looked ok so I'm assuming the issue is with the seals ?
Do you have to put a thin bit of wood in between the pistons, otherwise is there a possibility of the pistons compleatly popping out.
Not sure whether you've been told but the way to check for brakes binding is with wheel off the ground, actuate the brakes hard for approx 4 seconds release and immediately try to spin the wheel if they are binding there will momentarily be resistance. Best to have hold of the wheel before releasing the brakeI wouldn't and don't use red rubber because 1. it would attract crap to stick 2. according to my Yam dealer, too much can have a negative impact on the seals and should only be used sparingly to help initial installation and whether or not that is the case 3. the brake fluid lubricates the piston anyway. Before removing the pads i push both pistons fully in then remove pads and clean the caliper with a tooth brush. put a spanner between the slot and then a wedge between the spanner and one of the pistons so that I can pump one piston out at a time to clean. Once cleaned if they are still binding a bleed may finish the job