1989 Honda FL400R Pilot Service Manual, Page 201Get this manual
BRAKE DISC WARPAGE Measure brake disc for warpage
SERVICE LIMIT: 0.2 mm (0.008 in)
BRAKE DISC REPLACEMENT
Remove the left drive shaft (page 13-19)Remove the brake caliper (page 14-13 Remove the brake disc bolts and brake disc
Install new brake disc with its arrow mark facing outside
Make sure that direction of arrow mark on the brake disc is the same direction as brake disc hub rotates