Brother GT-3 Series Service Manual page 256

6. Replacing Parts
20. Rotate the Gear (23) inside with your hand to move the Caps down.
(23)
21. Move the Carriage (24) with your hand and confirm if the Tubes are moving smoothly; no kink, no stretch,
no touching or no damage.
(24)
Confirm not to touch with other parts
GT-3 Series
247