(12)
Do the test at each of the four brake locations.
(13)
Make sure the quantity of fluid collected in the container from all four brakes is not more than 0.75 gallon.
(14)
Fill the hydraulic reservoirs (Ref 12-12-00/201).
(15)
Put the airplane back to its usual condition.
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May 01/01 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 32-41-0 Page 203
HYDRAULIC BRAKE SYSTEM - ADJUSTMENT/TEST
1. General
A. After repair or replacement of linkage or cables, the mechanical portion of the brake control system must be rigged. Adjustments are made until brake pedals reach correct angle of slope. Linkage and cables are then adjusted until metering valves are closed.
B. The hydraulic brake system is tested to check the function of the entire system. Tests are made on periodic inspection or on brake malfunction report. Pressure is checked at accumulator and brake lines. Brakes are checked at wheels for correct operation and for automatic response.
C. The surrounding temperature of the airplane should be stable for one hour prior to rigging.
2. Adjust Hydraulic Brake System
A. Equipment and Materials
(1)
Rigging pins, 5/16-inch diameter by 10-inches long. Four required
(2)
Cable Tensiometer, 0-200 pounds
B. Adjust Brake Control Linkage
(1)
Put chocks on the wheels and release the parking brake.
(2)
Operate the rudder pedal adjustment crank (Fig. 501) to put the rudder pedals of the captain or the first officer in the neutral position.
NOTE: Count the number of times the crank turns from the full forward and the full aft adjustment to find the middle position.
(3)
Install a rigging pin through the floor beams and the bellcranks below each pair of rudder pedals (Fig. 501).
(4)
Install the rigging pins through each pair of rudder pedal arms (Fig. 501).
NOTE: To permit the rigging pin installation in the rudder pedal arms, adjust the tie rods (Fig. 502) by the procedure that follows:
(5)
Disconnect the right end of the tie rods.
(6)
Install the rigging pins through the bellcranks.
(7)
Loosen the jamnuts and adjust the length of the tie rods until you can freely install the rod end bolts.
(8)
Tighten the jamnuts and replace the rod end bolts.
(9)
Make sure that the rigging pins are loose and you can see the inspection holes of the rod end threads.
(10)
Place a square against each brake pedal and adjust the pushrod until the pedal tips are
3.06 + 0.26/-0.21 inches from square (Fig. 501).
500
Aug 01/96 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 32-41-0 Page 501
C. Adjust Main Gear Brake Control Cables.
(1)
Loosen main gear brake cables LGBA and LGBB at turnbuckles.
(2)
Tension cables LGBA first then cables LGBB per table 1 (Fig. 502).
(3)
Install turnbuckle locking clips.
(4)
Lockwire turnbuckles of cable systems LGBA, LGBA’ and LGBB, LGBB’ together with lockwire. (See Detail A, Fig. 502)
(5)
Remove rigging pins.
3. Test Hydraulic Brake System
A. Equipment and Materials
(1)
Pressure gages - 0 to 3500 psi for hydraulic fluid (4 required)
(2)
Hydraulic service cart - 0 to 3000 psi
(3)
Gear Ground Lock Assemblies - F72735 (Ref 32-00-01)
B. Prepare to Test Hydraulic Brakes
(1)
Chock wheels and release parking brakes.
(2)
Connect external electrical power.
(3)
Check that main and nose landing gear ground lock assemblies are installed (Ref 32-00-01).
(4)
Depressurize hydraulic System A and B (Ref 29-11-0, 29-12-0 MP).
(5)
Depressurize brake system accumulators by operating brakes fully for three times. Check accumulator gages to agree with placard. Adjust precharge pressure if required.
(6)
Remove upper bleed screw at each brake and install pressure gage at each upper bleed port.
(7)
Check brake system plumbing continuity.
(a)
Check that ground interconnect valve circuit breaker located on panel P6 is open and is suitably tagged to prevent inadvertent closing during brake system test.
(b)
Check that ground interconnect valve is closed and valve position indicator is on position 1.
(c)
Pressurize hydraulic system B to 3000 psi through the ground power modular unit using hydraulic service cart (Ref 29-12-0). Depress and hold brake pedals. 1) Check pressure to be 3000 + 100 psi at each outboard wheel brake gage. 2) Check that each inboard wheel brake gage indicates return pressure (50 psi or
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