Honda TRX500FM Owner's Manual page 154

Rear Brake Pedal Freeplay
RIGHT SIDE
(1) rear brake pedal
Inspection
Measure the distance the rear brake pedal ( ) moves before the brake
starts to take hold. Freeplay, measurement at the tip of the end of the
pedal, should be:
9/16 13/16 in (15 20 mm)
If necessary, adjust to the specified range.
Brakes
(1)
9/16 13/16 in
(15 20 mm)
1
Servicing Your Honda 145