Brother DCP-L8400CDN Service Manual page 246

(3) Remove the Separation support film and ADF separation pad from the Upper ADF chute.
Upper ADF chute
Note:
If the edge of the Separate support film protrudes from the Upper ADF chute, it causes
noise.
ADF separation pad
Separate support film
Upper ADF chute
Separate support film
Fig. 3-90
Upper ADF chute
ADF separation pad
Upper ADF chute
Fig. 3-91
3-82
Separation support film
ADF separation pad
ADF separation pad
Separate support film
Confidential