32-11-02
 ALL  ú ú 01A Page 823 ú Oct 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

 CAUTION:_______ KEEP THE GLAND NUT AND THE OUTER CYLINDER TOGETHER AS A
 SET.  IF THE OUTER CYLINDER THREADS WERE REWORKED, THE
 GLAND NUT WOULD BE UNIQUE TO THE OUTER CYLINDER.  A
 DIFFERENT GLAND NUT WILL NOT FIT THE OUTER CYLINDER
 TIGHTLY AND CAN CAUSE THE LANDING GEAR FAILURE DURING THE

 OPERATION.
 (b)  
Remove the gland nut lockplate and use the wrench adapter to loosen the gland nut (9).

 (c)  
Move the gland nut (9) down to the inner cylinder yoke.

 (d)  
Lift the airplane (or lower the truck into a pit) if it is necessary.

 (e)  
Give the clearance for the installation of the lower bearing puller.

 CAUTION: CLEAN THE HYDRAULIC FLUID FROM THE TIRES IMMEDIATELY IF
_______ THE FLUID GETS ON THE TIRES. HYDRAULIC FLUID WILL CAUSE DETERIORATION OF THE TIRES.
 (f)  
Move the scraper ring and the retainer down to the gland nut (9).

 (g)  
Put a tray below the shock strut to catch the hydraulic fluid.

 (h)  
Attach the lower bearing puller to the lower bearing (12) with three screws.

 (i)  
Attach the sleeve of the puller to the chrome surface of the inner cylinder (13).

 (j)  
Lift the airplane or lower the inner cylinder (13) until you can get the seal (6).

 (k)  
Move the lower bearing (12) and the seal retainer down to the gland nut (9) at the top of the yoke.

 (l)  
Continue to lift the airplane or lower the inner cylinder (13) until you have sufficient clearance to remove the seal (6).

 (11)
 Install the spare seals.

 S 428-055
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 32-11-02
 ALL  ú ú 02A Page 824 ú Feb 10/93
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

 CAUTION:_______ PUT A PROTECTION STRIP BETWEEN THE SEAL AND THE SURFACE OF
 THE INNER CYLINDER WHILE YOU CUT THE SEAL.  THIS WILL
 PREVENT THE DAMAGE TO THE SURFACE OF THE INNER CYLINDER.
 THE NICKS OR THE SCRATCHES ON THE INNER CYLINDER WILL
 CAUSE DAMAGE TO THE INNER CYLINDER.  THEY WILL ALSO CAUSE
 DAMAGE TO SEALS WHILE THE SEALS MOVE THROUGH THE NICKS OR

 SCRATCHES.
 (a)  
Cut the seal (8) from around the inner cylinder (13).

 (b)  
Use the plastic tool to prevent damage to the inner cylinder surfaces.

 (c)  
Remove the backup rings (11) from the recess in the lower bearing.

 S 118-057
 (12)
 Clean the inner cylinder (13) and the other parts fully with hydraulic fluid.

 S 218-058

 (13)
 Examine that all the backup rings (7 and 11) are serviceable.

 (a)  
Replace the backup rings if they have nicked, scratched or damaged.

 NOTE: The recommended installation is to replace the used
____ backup rings with new backup rings. Use the used backup rings only after a full inspection when new rings are not available.
 (b)  Examine that the scraper rings are serviceable.
 S 428-059
 (14)
 Install the new active seals.

 (a)  
Carefully move the seal (8) up into the groove in the top of the lower bearing.

 (b)  
Use the blunt nonmetallic tool if it is necessary to fully set the seal (8) in the recess.

 (c)  
Examine that the seal is not twisted.

 (d)  
Apply a light layer of hydraulic assembly lubricant if it is necessary.

 (e)  
Install the backup rings (11).

 (f)  
Make sure that the backup rings (11) touch the inner cylinder surface.

 (g)  
Move the seal (6) (larger diameter seal) up into the outer groove of the lower bearing.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
　
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