Canon iPF8400S Service Manual page 147

Never peel off tape [1] that fixes the ink tube when detaching the joints of the ink tube on the upper part of the carriage or when removing the joint base from the
carriage.
8) Twist off belt fixer knob [1] to loosen the belt, and remove spring [2], guide [3] and pulley [4].
9) Release carriage belt from the pulley of the carriage motor.
[1]
F-4-30
[3]
[4]
F-4-31
[2]
[1]
Chapter 4
4-17