S 942-014
(10)
Remove the wheel chocks.
TASK 32-41-00-702-022
3. Antiskid Module Hydraulic Brake Fuse Test
_________________________________________
A. General
(1)
The normal and alternate brake systems have hydraulic fuses to decrease the loss of system fluid of the brake lines break downstream of the fuse.
(2)
This task is a test to make sure that the fuse operates to limit the quantity of fluid loss from the hydraulic system when leakage occurs. The test is repeated for each fuse in the system.
B.
Equipment
(1)
Container - 3 U.S. gallon capacity
C.
Consumable Materials
(1)
D00153 Hydraulic Fluid - BMS 3-11, Type IV
D.
References
(1)
AMM 12-12-01/301, Hydraulic System
(2)
AMM 29-11-00/201, Pressurize/Depressurize Main Hydraulic System
(3)
AMM 32-00-15/201, Landing Gear Door Locks
(4)
AMM 32-00-20/201, Landing Gear Downlocks
(5)
AMM 32-44-00/001, Parking Brake System
E.
Access
(1)
Location Zones
143 MLG Wheel Well (Left)
144 MLG Wheel Well (Right)
731 Left Main Landing Gear (MLG)
741 Right Main Landing Gear (MLG)
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F. Prepare to Test the Brake System Fuses
S 492-015
(1) Make sure that the downlocks are installed on the main and nose landing gear (AMM 32-00-20/201).
S 492-016
WARNING: USE THE PROCEDURE IN AMM 32-00-15/201 TO REMOVE THE DOOR LOCKS.
_______ THE DOOR LOCKS OPEN AND CLOSE QUICKLY AND CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.
(2)
Open the doors for the landing gear and install the door locks (AMM 32-00-15/201).
S 862-023
(3)
Make sure that the parking brake is released.
G.
Test of Brake Fuses Capacity
S 722-017
(1)
Do a test of normal brake system fuses capacity.
(a)
Remove the screw from the end of the bleeder valve and install a bleed hose on the end of the bleeder valve.
(b)
Put a container with a minimum capacity of 3 U.S. gallons near the brake bleeder valve so that fluid goes directly into the container.
(c)
Pressurize the right hydraulic system and reservoir (AMM 29-11-00/201).
(d)
Push the brake pedals all the way in and hold.
NOTE: The parking brake may be used to hold the brake pedals
____ fully pushed in for fuse check.
(e) While you apply full brake pressure, open the brake bleeder valve one-half turn. Let the fluid flow into the container until the flow stops. This shows that the fuse has closed.
NOTE: Fluid can flow out of the hose very quickly and
____ intermittently. Be sure that the flow goes into the container.
(f)
When the flow stops, check that the quantity collected in the container is 0.28-0.36 gallon.
(g)
Reset the fuse. Hold the fuse knob in the bypass position for 5 seconds minimum to make sure that the fuse resets.
(h)
Remove the bleed hose and install the screw and washer in the end of the bleeder valve.
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(i) Do the above test again for each fuse at each of the eight brake positions.
NOTE: The hydraulic reservoir quantity should be monitored
____ carefully. The normal brake system test series will use approximately 2.8 gallons of hydraulic fluid.
Check that the quantity collected does not exceed 3 gallons total from all brakes (8 locations).
S 612-018
(2)
Do the servicing procedure for the right hydraulic system reservoir (AMM 12-12-01/301).
S 432-019
(3)
Tighten the bleeder valve if you will not do the alternate brake system fuse capacity test now. Tighten as follows:
(a)
Tighten the bleeder valve on B.F. Goodrich brakes to 35-55 pound-inches.
(b)
Tighten the bleeder valve on Dunlop brakes to 8 pound-feet.
S 722-024
(4)
Do a test of alternate brake system fuses capacity.
(a)
Remove the screw from the end of the bleeder valve and install the bleed hose on the end of the bleeder valve.
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