TM 5-4130-234-13&P
Section III. TROUBLESHOOTING
nor all tests or inspections and corrective actions. If a
3-6.
General
malfunction is not listed or is not corrected by listed
This section contains troubleshooting information for
corrective actions, notify your supervisor.
locating and correcting most of the operating troubles
which may develop in the refrigeration system service unit.
3-8.
Troubleshooting Refer to table 3-2
for
Each malfunction for an individual component, unit, or
system is followed by a list of tests or inspections which will
troubleshooting information.
help you to determine probable cause and corrective
NOTE
actions to take. You should perform the tests/ inspections
Before you use this table, be sure you
and corrective actions in the order listed.
have performed all applicable operating
checks.
3-7.
Malfunctions
This manual cannot list all malfunctions that may occur,
Table 3-1. Operator/Crew Preventive Maintenance Cheeks and Services
B - Before Operation
D - During Operation
A - After Operation
Time required: 1.6
Time required
Work
Interval
Item to be Inspected
Time
and
(M H)
Sequence No.
Procedure
1.6
B
D
A
6
VACUUM PUMP
1
0.1
Inspect pump oil through glass disk for proper oil level. Oil level must be at bottom of glass
disk.
0.1
Inspect pump oil through glass disk for foreign matter and vapors formed sludges.
ACCESSORIES
2
0.2
Inspect all accessory hose assemblies for cleanliness.
GAGES AND GLASS SCALE
3
0.3
Inspect gages for broken glass and for broken pointers.
0.1
Inspect glass tube and beaker for cracks or leakage.
0.1
Inspect glass parts for cleanliness.
VALVES AND UNIONS
4
Check valves for binding and insecure mounting.
0.2
Inspect valves and unions for damaged or crossed threads.
0.3
FRONT OF ENCLOSURE
5
Inspect all components for security.
0.1
Inspect enclosure and attached components for cleanliness.
0.1
Table 3-2. Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. SERVICE UNIT FAILS TO REACH ULTIMATE VACUUM.
Step 1. After vacuum pump has been running for at least 15 minutes, check the oil level through glass window.
The level must be within sight of glass window while the pump is in operation. In general, the oil level
will be slightly higher while the pump is running. If oil level is not within view of glass window, stop pump
and fill to proper level.
Step 2. Inspect oil for contamination through glass window. Contamination is caused by condensation of vapors
and by foreign matter entering the pump. If oil appears contaminated, drain, flush and replace vacuum
pump oil.
Step 3. Check plumbing for leaks using the leak detector. If leakage is detected, isolate and repair leak.
Step 4. Inspect vacuum pump for oil leaks between motor and pump, oil case, and sight glass. Repair leakage
in accordance with chapter 6.
3-2
