My front breaks squeek and grab. I have tried cleaning with break cleaning fluid. Have tried spraying the back part of the break pad with "brake quiet". I don't see any major scratches, but a thin line off brownish "film" running around the rotor. May I pull off the rotor and use a sander to remove the film? The pads are almost new.
Mmmm! My guess is the forks seals or the calliper are starting to leak and are working their way onto the disc. Best check both these first. If this is the case the pads will be contaminated & will never work as well again.
If it is just glazing & the disc is straight, then sanding the glazing off is the acceptable fix. (if it was coned it would rub in that area & cause the marks you talk of, check with a ruler)
I should mention, oops, I recently had my front shocks rebuilt because of leaking shock fluid. Would this ruin the pads or create the film on the rotors? Is it sensible to sand rotors now?