27-09-51
ALL ú ú 01 Page 404 ú Nov 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 737-300/400/500MAINTENANCE MANUAL
LOW PRESSURE WARNING SWITCH - REMOVAL/INSTALLATION
__________________________________________________
1. General
_______
A. This procedure contains two tasks. There is a task for the removal and a task for the installation of the low pressure warning swich.
B. The low pressure warning switch is part of the flight controls modular package. The modular package for hydraulic system A is found in the left main wheel well. The modular package for hydraulic system B is found in the right main wheel well.
TASK 27-09-61-004-025
2. Low Pressure Warning Switch Removal
___________________________________
A. References
(1)
AMM 29-09-00/201, Hydraulic Reservoir Pressurization System
(2)
AMM 29-15-00/201, Hydraulic Systems A, B, and Standby
B.
Access
(1)
Location Zones
101/102 Control Cabin - Left/Right
216/217 Left/Right Main Wheel Well
C.
Prepare for Removal
S 044-002
(1)
Do this task to depressurize hydraulic systems A and B: "Hydraulic System A, B or Standby Depressurization" (AMM 29-15-00/201).
S 044-003
(2)
Do this task to depressurize hydraulic system A and B reservoirs: "Hydraulic Reservoirs Depressurization" (AMM 29-09-00/201).
S 864-006
(3)
Open these circuit breakers and attach DO-NOT-CLOSE tags:
(a)
P6 Panel
1) IND LIGHTS
D.
Remove the Low Pressure Warning Switch
S 024-021
(1)
Remove the switch (Fig. 401):
(a)
Disconnect the electrical connector from the switch.
(b)
Remove the switch from the modular package.
(c)
Use a container to catch hydraulic fluid that drains from the switch.
(d)
Put a cover on the modular package housing to keep (unwanted) material out of the open port in the modular package housing.
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27-09-61
ALL ú ú 02 Page 401 ú Nov 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 737-300/400/500MAINTENANCE MANUAL
LOCKWIRE
SEE A
LOW PRESSURE WARNING SWITCH
HOUSING
A
Low Pressure Warning Switch Installation
Figure 401
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27-09-61
ALL ú ú 02 Page 402 ú Nov 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
TASK 27-09-61-404-026
3. Low Pressure Warning Switch Installation________________________________________
A. Consumable Materials
(1)
D00288 Lubricant, Skydrol Assembly - MCS 352
(2)
D00148 Fluid-Hydraulic, BMS 3-11, Type IV, Class 1
B.
References
(1)
AMM 12-12-00/301, Hydraulic Reservoir
(2)
AMM 27-09-61/501, Low Pressure Warning Switch
C.
Access
(1)
Location Zones
101/102 Control Cabin - Left/Right
216/217 Left/Right Main Wheel Well
D.
Install the Low Pressure Warning Switch
S 424-023
(1)
Install the switch (Fig. 401):
(a)
Lubricate the O-rings and backup rings with hydraulic fluid or assembly lubricant.
(b)
Install the O-ring with backup rings on the switch.
(c)
Install the switch on the modular package.
(d)
Tighten to 50-200 pound-inches.
(e)
Install a lockwire on the switch to the mounting bolt.
(f)
Connect the electrical connector to the switch.
