The brakes on a busa are self adjusting . When replaceing brake pads on the front or rear, You do not have to bleed them,,
All that is needed to do is drop your old pads and compress the piston back into the cylinder slowly until it is flush with the caliper,,This technique is also done on autos,,only on the newer fords do you have to use a special compression tool that turns the piston in the caliper as it is compressed,, but Most motorcyle dealerships do not bleed them,,unless you are replaceing brake lines or have a leak or te bike is old and you want fresh fuid,,but compress the piston back slowly, some even break loose the brake resevoir lid slightly,but it is not necessary,,, after replaceing the front or the rear brakes,,the owners manual instructs you to rapidly pump the brake lever multiple times and the brake caliper piston will adjust itself automatically,,,
Sounds like [if their spongy] you probually have air in the lines,,,,One thing that I really like about the busa is replaceing the brake pads either front or back is easy,,,,and also,,alot of people make the mistake of takeing off the caliper to change the brakes,,,,thats a no-no..alot of extra unnecssary work ,and caliper bolts can be a bear to break loose on some models,,,to check the wear on the rear,there is a plastic ,pop off cover and useing a small mirrror you can clearly see the pads as advised by the manual,,,,check your lines and fluid view window[for leaks] and pump up the brakes by rapidly pumping the brake pedal[while not running] to see if you can get a full peda , the release the brake leverl,,,then wait a minute and gradually press down on the pedal by steady pressure,,,if it slowly goes down a bit while holding it,,,you have air in the lines,,,,,to be on the safe side,,,call the dealership after you have took a mirror and inspected the barake pads yourself to see if theres a crack or the brake pad plates were put back on the back of the pads,,then call and ask if they bled them or not,,,,even after all this,,I would still bleed them and you need a secound person to do it right,,pm me if you need help,,,,