nissin caliper chocking ?

[britishgas]

I have been told by a gas gas dealer to pad out the nissin rear caliper by added a worn brake pad to the piston side too stop th e brake working poorly as soon as the pads wear slightly. My question is is this safe ?

 

[bowhunter007]

Strange, my brakes work fine as long as there's material still on the plate. Is the piston sticking, or a bit of air in the system?