Honda FourTrax Foreman TRX500FM2 2018 Owner's Manual page 189

Rear Brake Lever Freeplay
LEFT HANDLEBAR
15 – 20 mm
(0.6 – 0.8 in)
(1) rear brake lever/parking brake lever
Inspection
Measure the distance the rear brake lever/parking brake lever (1)
moves before the brake starts to take hold. Freeplay, measurement
at the tip of the end of the brake lever, should be:
15 – 20 mm (0.6 – 0.8 in)
If necessary, adjust to the specified range.
(1)
Brakes
Servicing Your Honda 179