Brother  HL-4140CN User Manual page 195

j
Put a piece of paper (A4 or Letter) on the
belt unit to prevent damage to the belt
unit.
k
Make sure the green lock lever (1) is in
the release position as shown in the
illustration.
1
Routine maintenance
l
Match the guide ends (2) of the drum
unit to the c marks (1) on both sides of
the machine, then gently slide the drum
unit into the machine until it stops at the
green lock lever.
1
2
m
Turn the green lock lever (1) clockwise
to the lock position.
A
1
25