2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 410Get this manual
HYDRAULIC BRAKE Pivot the caliper body up and remove the brake pads from the caliper bracketAlways replace the Install new brake pads into the caliper bracket with brake pads in pairs the shim facing toward the piston sideto ensure even disc|the| pressuregTORQUE: 23 (2.3 kgf m, 17 Ibfft) Depress the brake pedal to seat the caliper piston against the pad
BRAKE DISC INSPECTION
For front brake disc, remove the front wheel (page 17-11)Visually inspect the brake disc for damage or crackMeasure the brake disc thickness at several pointsSERVICE LIMITS: Front: 2.5 mm (0.10 in) Rear: 3.5 mm (0.14 in) Replace the brake disc if the smallest measurement is less than service limit