Honda FourTrax Rancher TRX420FA5 2019 Owner's Manual page 176

Brakes
Rear Brake Fluid Level
RIGHT REAR
(1)
(2)
(1) UPPER level mark
With the ATV on a level surface, check the fluid level.
It should be between the UPPER (1) and LOWER (2) level marks. If the
level is at or below the LOWER level mark, check the brake pads for
wear (page 167).
Worn brake pads should be replaced. If the pads are not worn, have
your brake system inspected for leaks.
Other Inspections
• Make sure there are no fluid leaks.
• Check for deterioration or cracks in the hoses and fittings. If the
hoses are worn or cracked, have them replaced by your dealer.
166 Servicing Your Honda
(2) LOWER level mark