I had to tear down the rear brakes to install a new master cylinder and discovered that the brake shoes are identical - FE18723. I know the primary is supposed to be shorter than the secondary. Short in front, longer in back. I have read that some M715's have equal length shoes in the rear - but I can't confirm. Looking at the way the shoes were positioned in the drum, the rear one wasn't riding inside the backing plate at all. My question to all and sundry is: what is the truth?