Component Maintenance Manual
EFFECTIVITY: ALL
21-00-22
Page
1002
JULY 21, 2011
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.
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.
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.
SUBTASK 21-00-22-70-003
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)
R12 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
Thread sealant primer, PN 7471 (Loctite)
Thread sealant, PN 569 (loctite)
Hose adapter (1/2 in. male acme to ¼ in. female flare)