(d)
Adjust the hook open switches to operate at this point: 1) Measure the continuity through the hook open switch. 2) Move the hook open switch in its bracket until it opens.
NOTE: You will know the switch opens when there is no
____
continuity through it.
S 824-042
(5) Adjust the hook closed switches:
NOTE: These steps are for the forward and the aft hook closed
____
switches.
(a) Close the hooks but keep the door open: 1) Make sure the door is open far enough to get access to the hooks.
2) Push the plungers into the two door down switches (S1231 & S1232) with a suitable tool.
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747-400 MAINTENANCE MANUAL
3) Hold the door control switch in the CLOSE position until electrical operation stops.
NOTE: The hooks and latches will move to the closed
____ position and the door will not move.
CAUTION: THE STEP THAT FOLLOWS WILL CAUSE AN OUT-OF-SEQUENCE
_______ POSITION OF INTERRELATED MECHANISMS. THEY MUST BE RESTORED AFTER ADJUSTMENTS HAVE BEEN MADE.
4) Remove the tool from the door down switches.
(b) Turn the manual drive of the hook actuator clockwise until the internal stops touch each other: 1) Use a dial indicator torque wrench to manually turn the
actuator clockwise at 25 |5 pound-inches torque. 2) Manually turn the actuator until the torque increases by 15-20 pound-inches. 3) Turn the manual drive 1/2 turn counterclockwise
NOTE: The internal stops are at this point.
____
(c)
Turn the manual drive counterclockwise 9 turns.
(d)
Adjust the hook closed switch: 1) Measure the continuity through the hook closed switches. 2) Move the hook closed switch in its bracket until it opens.
NOTE: You will know the switch opens when there is no
____
continuity through it.
(e) When the two switches are adjusted, hold the door control switch in the open position until the lift mechanism starts to lift the door. Release the door control switch.
NOTE: This will return the hooks and latches to the open
____ position and will put the door to the correct in-sequence position.
S 824-032
(6)
Adjust the latches open switch (Fig. 409):
(a)
Fully close the door.
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MAINTENANCE MANUAL
CAUTION:_______ IN CASE THE DOOR DOES NOT OPEN, STOP IMMEDIATELY. DO NOT
OPERATE THE DOOR CONTROL SWITCH. HOLDING THE DOOR CONTROL
SWITCH MAY DAMAGE THE ACTUATOR. WAIT AT LEAST 1 MINUTE
BEFORE SECOND ATTEMPT. IF THE DOOR STILL DOES NOT OPEN,
WAIT AT LEAST 10 MINUTES BEFORE THIRD ATTEMPT.
(b) Open the door electrically one to two feet (until the latch operation stops).
NOTE: The door must be opened electrically because the latch
____ position at the electrical shutoff shows you if the switch setting is correct.
(c)
Use a dial indicator torque wrench to apply 25 |5 pound-inches torque to manual drive of latch actuator in the counterclockwise direction.
(d)
Carefully count the remaining turns until the external stops touch each other (open position) (Fig. 403). The external stops must touch in 3 |1 turns.
(e)
If the external stops do not touch in 3 |1 turns, do these steps: 1) Subtract the actual number of turns from the 3 |1 turns
that are necessary. 2) Subtract this difference from 8 |1/4 turns. 3) From the position when the external stops touch each other,
turn the manual drive 15 turns clockwise. 4) Disconnect the electrical connector DX225C from the cargo door junction box.
5) Adjust the switch until there is continuity between pins 21 and 22 of connector DX225C as the latch actuator is turned counterclockwise the number of turns given above.
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