G.
Install Steering Metering Valve (Fig. 401)
S 494-077
WARNING: YOU MUST CAREFULLY INSTALL THE GROUND LOCKS IN ALL
_______ LANDING GEAR. AN ACCIDENTAL RETRACTION OF THE LANDING GEAR CAN CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.
(1) Install the ground locks in all landing gear (AMM 09-11-00/201).
S 494-061 WARNING: YOU MUST CAREFULLY DO THE STEPS IN THE TASK BELOW TO INSTALL
_______ THE DOOR LOCKS ON THE LANDING GEAR DOORS. THE DOORS CAN CLOSE QUICKLY IF YOU DO NOT INSTALL THE DOOR LOCKS CORRECTLY.. THIS CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.
(2)
Do this task: "Installation of the Door Locks on the Nose Landing Gear" (AMM 32-00-30/201).
S 844-063
(3)
Release pressure from hydraulic system No. 1 (AMM 29-11-00/201). S 434-052
(4)
Do this task if the trunnion bearings were removed: "Install Trunnion Bearings (Fig. 401)" (AMM 32-51-12/401)
S 614-017
(5)
Make sure that the valve is completely filled with hydraulic fluid. S 434-018
(6)
Remove the valve input arm from the valve and connect it to the connecting rod.
NOTE: It is optional to remove the input arm.
____
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747-400 MAINTENANCE MANUAL
(7) S 434-019Install new 0-rings on the seal tubes between the valve and the cylinder trunnions, and cap the fittings.
(8) S 434-020Insert the three metering valve attach bolts (1 and 2) with three washers (3) into the steering metering valve before positioning the valve.
S 424-021
CAUTION: THE VALVE WILL NOT FUNCTION IF THE INDEX MARKS ARE 180 DEGREES
_______ OUT OF ALIGNMENT. THE VALVE CANNOT BE PHYSICALLY POSITIONED CORRECTLY IF THE INDEX MARKS ARE NOT ALIGNED.
(9)
Make sure that the circular index marks on the top surface of each valve and valve housing are aligned on the forward side of the trunnion.
S 434-074
(10)
Position the steering metering valve.
S 434-022
CAUTION: THE TWO ENDS OF THE VALVE ASSEMBLY MUST BE KEPT AT THE SAME
_______ LEVEL DURING INSTALLATION. UNEVEN TIGHTENING OF THE LEFT AND RIGHT RETAINER NUTS CAN CAUSE VALVE ASSEMBLY TUBE DAMAGE.
(11)
Tighten the valve retainer nuts, evenly on two ends from 700 to 750 pound-inches torque.
S 434-075
(12)
Install the attach bolt washers (3) and attach mounting nuts (5), and tighten the attach mounting nuts (5).
S 624-023
(13)
Apply corrosion preventive compound on the bottom of the upper trunnion bearing and the top of the lower trunnion bearing.
S 114-024
(14)
Clean the area around the retainer nuts, for a new sealant bead, with a new or laundered white lint-free cloth wet with toluene.
(a)
Do not use too much cleaner.
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S 114-025
CAUTION:_______ SILICONE MATERIALS CAN CONTAMINATE EACH OTHER AS WELL AS OTHER
MATERIALS. THUS, THOROUGH CLEANING AND SEPARATE AREAS AND
EQUIPMENT ARE NECESSARY.
(15)
Remove all the solvent from the faying surfaces with compressed air.
S 114-055
(16)
After blasting with air, make a final cleaning with a cloth just damp with solvent and then wipe dry.
S 674-026
(17)
Apply a thin brush layer of primer to the seal area of the retainer nuts and permit a minimum of 1/2-hour drying time before applying the sealant.
S 344-027
(18)
Apply a bead of sealant around the retainer nuts using a sealing gun.
(a)
Put the nozzle tip nearly perpendicular to the line of travel, forcing a bead of sealant ahead of the nozzle tip.
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