Brother MFC620CN Service Manual page 197

Removing the maintenance unit and related parts
(2) Remove two screws, "e" from the top of the engine unit and "f" from the right side of the
maintenance unit.
(3) Remove the maintenance unit.
(4) Unlatch the purge cam switch from the maintenance unit.
(5) Remove the purge-related parts from the engine unit as shown below.
NOTE: Take care not to let the springs bounce off.
Clutch gear spring (shorter)
Top of the maintenance unit
Purge lever
Engine unit
Reassembling Note: When setting the idle gear L back into place, face its ribs inwards.
Reassembling Note: If you replace the engine unit, make adjustments specified in
Section 6.2.
Clutch gear
Purge lever shaft
Purge lever
"e"
Ribs
PF roller gear R
5-59
Purge lever spring (longer)
"f"
Maintenance
unit
Idle gears S
Purge gear
Idle gear L
"e": Taptite, cup B M3x8
"f": Taptite, cup S M3x6
Purge cam switch
Latch
Chapter 6,
Conf idential