Honda FourTrax Rancher TRX420TE1 2020 Owner's Manual page 174

Brakes
Rear Brake Pedal Freeplay
RIGHT SIDE
(1) rear brake pedal
Inspection
Measure the distance the rear brake pedal (1) 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.
164
Servicing Your Honda
(1)
9/16 – 13/16 in
(15 – 20 mm)