(a)
Do not use too much force. This will tighten the piston shaft against the bleed valve clevis rod until bottomed.
F.
Procedure
S 735-089-N00
(1) Check operation of equipment as follows:
WARNING: MAKE SURE ALL PERSONS AND TOOLS ARE AWAY FROM THE
_______ MECHANICAL PARTS OF THE BLEED SYSTEM. WHEN YOU START THE PUMP, THE ACTUATOR CAN MOVE. IF YOU DO NOT DO THIS, YOU CAN CAUSE INJURY TO PERSONS AND DAMAGE TO THE ACTUATOR OR THE ENGINE CAN OCCUR.
(a) Service the pump with the Calibrating Fluid (P03-003) and connect to a power source.
NOTE: If you do not know how to service and operate the
____ hydraulic pump, see the instructions for hydraulic pump service and operation (AMM 75-32-01/201).
(b)
Supply 100 psig to the actuator aft pressure adapter.
(c)
Set the POWER switch on the PWA 85842 Electrical Control Box to the ON position.
(d)
Use the Electrical Control Box to cycle the bleed valve back and forth between open and closed positions to make sure the
2.5 bleed valve assembly moves freely.
(e)
After cycling the bleed valve, leave the bleed valve in the closed (actuator piston shaft forward) position.
(f)
All actuation of the bleed system to the valve open or valve closed positions should now be done with the PWA 85842 Electrical Control Box OPEN/CLOSE switch.
(g)
Keep 100 psig pressure to the actuator during all measurements.
S 735-090-N00
(2) Check the travel of the piston as follows:
NOTE: All measurements must be made with 100 psig at the
____ actuator, use a depth micrometer and measure from the piston shaft to the same location on the housing.
(a) Measure the length of piston travel as follows (Fig. 501, View C-C, Piston Travel Check): 1) Establish a stationary reference point on the actuator
housing to be used for all piston travel measurements which follow. 2) Make sure the bleed valve is in the closed (actuator piston shaft forward) position.
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75-32-01
ALL ú ú N01 Page 512 ú Jun 18/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
3) Measure the distance from the piston shaft end to the
reference point on the actuator housing.
4) Record as Dimension B.
5) Actuate the bleed system to the valve open (actuator piston
shaft rearward) position.
6) Measure the distance from the piston shaft end to the
reference point on the actuator housing.
7) Record as Dimension A.
8) Determine piston travel by subtracting Dimension B from
Dimension A.
9) Record the result as Dimension C.
10) Piston travel should be 2.280-2.320 inches
(87.91-58.93 mm).
(b)
If the piston travel is not within limits, repeat the
measurement.
(c)
If the piston travel is still not within limits, check to make sure the piston shaft is fully against the bleed valve clevis rod as follows: 1) Remove pressure to the actuator. 2) Turn the piston shaft hex clockwise (from rear) only until
the shaft stops. 3) Do not use too much force. 4) This will tighten the piston shaft against the bleed valve
clevis rod until bottomed.
(d) Supply 100 psig to the actuator and do the piston travel check again. 1) If the piston travel is still not within the limits,
replace the actuator.
S 735-091-N00
(3) Set the bleed valve compression as follows:
(a) Make the initial bleed valve compression adjustment as follows (Fig. 501, View C-C, Initial Compression Adjustment): 1) Remove the pressure from the actuator (0 psig). 2) Turn the piston shaft one turn counterclockwise. 3) Supply 100 psig pressure to the actuator again. 4) Actuate the bleed system to the valve closed (actuator
piston shaft forward) position.
5) Measure the adjusted dimension between the piston shaft end
and the established reference point on the actuator
housing.
6) Record the result as Dimension D. 7) Dimension D should be 0.015 inch (0.381 mm) minimum greater than Dimension B.
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