Component Maintenance Manual
12037 N Highway 99
Seminole, OK 74868
Phone (405) 382-0731
Fax (405) 382-0737
http://www.enviro-ok.com
Copyright © 2017
ATA 21-00-23
P a g e
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19
Revision 10
June 1, 2017
3.3.2.1
Verify that there is a distinct and noticeable change in sound of blower motor when
changing from low to high speed positions. This indicates that the cockpit selector
switch is functioning properly and that the blower motor is responding accordingly.
3.3.2.2
Verify that there is a smooth transition when changing from low to high speed
positions, and that there is no excessive noise or vibration coming from the blower
motor during the change. Excessive noise could indicate that the blower wheel is
rubbing against the blower scroll.
3.3.3
If there is excessive noise and/or vibration coming from blower motor/wheel assembly
during this test, please refer to Fault Isolation, Section 3.6, Disassembly procedures in
section 5 and Inspection procedures in section 7. This will help in identifying whether the
blower motor wheel is dirty or damaged and is need of repair or replacement, the blower
scroll is dirty or damaged and is need of repair or replacement, or the blower motor itself is
in need of replacement.
3.3.4
Verify that the system is cooling properly. If not, the expansion valve(s) might need
aligning. Refer to Special Procedures, Section 12, for Expansion Valve Alignment
procedures.
NOTE
: If a failure has occurred to the evaporator module assembly, a fault LED light will sometimes
illuminate inside the blower motor (1134200-60/-61/-63 evaporators only) and may be seen through the vent
cap/screen on the side of the motor. If technician observes the fault LED light, component must be removed
and replaced (refer to Disassembly, Section 5 and Assembly, Section 9).
SUBTASK 21-00-23-70-003
3.4
System Leak Check Testing Procedure:
3.4.1
A leak check of the refrigerant plumbing system is important to ensure the system maintains
its charge to provide the designed performance and reduce damage to system components.
A periodic check of the system charge is required to determine if any loss of refrigerant has
occurred.
3.4.2
A system leak check is required any time one or more of the following conditions occur:
•
New system plumbing installation
•
Component replacement in the plumbing system
•
Line or hose rupture
3.4.3
Special Tools and/or Equipment Required:
•
Gaseous dry nitrogen, regulated source (0-500 psig)
•
R-134A refrigerant charging manifold with gauges and hoses (low pressure gauge, 0-300
PSIG), (high pressure gauge, 0-600 PSIG)
•
Leak check fluid (soap solution), (Spec MS-SNOOP-GAL)
•
Assorted hand tools
•
Hand and eye protection
