Table 2-I. Troubleshooting--Continued
-
Probable Cause
Corrective Action
5. Dynamotor-welder exciter does not
a. Field coils defective.
furnished excitation voltage or
b. Brushes burned or badly worn.
b. Adjust brush spring tension or
voltage is below required level.
replace brushes TM 5-4940-225-
12.
c. Armature defective
d. Commutator dirty.
of
6. Abnormal
a. Replace brushes TM 5-4940 -225-
fluctuation
a. Brushes worn.
output
dynamotor-welder
current.
b. Increase brush tension TM 5-
b. Too little pressure of brushes on
4940-225-12
commutator.
c. Clean rheostat.
c. Rheostat contact dirty.
a. Replace bearings.
7. Compressor overheats.
a. Main or connecting rod bearings
defective.
b. Replace defective parts or gaskets.
b. Internal leakage.
c. Cylinder head gasket defective.
8. Compressor knocks.
a. (crankshaft bearings worn.
b. Piston pin and bearing worn.
c. Tighten or replace valve plates
c. Valve plates loose or broken.
a.Cylinder head gasket defective.
b. Piston and piston rings worn.
capacity.
c. Valve plates defective.
a. Piston rings worn.
excessive.
b. Cylinder worn.
Replace defective part.
11. Intercooler pop-off valve opens
High pressure suction or discharge
w h i l e running under load.
valve defective.
12. Intercooler pop-off valve opens
a. Low pressure unloader valve stuck
while running unloaded.
in loaded position.
b. Defective high pressure discharge
valve.
13.
Side doors
do
not
operate
a. Side lifting hydraulic pump
a. Repair side lifting hydraulic pump
properly.
defective.
b. Door hinge broken.
c . Cylinder defective.
See TM .5-4520 -209-15.
See TM 5-4520-209-15.
14. Personnel heater fails to ignite.
Section
III.
RADIO
INTERFERENCE
SUPPRESSION
components have radio interference suppression
2-6. General Methods Used to Attain Proper
Suppression
functions which are incidental or secondary to their
primary function.
Essentially, suppression is attained by providing a
2-8. Replacement of Suppression Components
The methods used include shielding the ignition
Refer to figure 2-1 and replace the radio in-
and high-frequency wires, grounding the frame
terference suppression components.
with bonding straps, and using capacitors and
2-9. Testing of Radio Interference Sup-
resistors.
pression Components
2-7. Interference Suppression Components
Test the capacitors for leaks and shorts on a
a. Primary Suppression Components. T h e
capacitor testor; replace defective capacitors. If
primary suppression components are those whose
primary function is to suppress radio interference.
indicated, isolate the cause of interference by the
These components are described and located in
trial and error method of replacing each capacitor
b. Secondary Suppression Components. These
eliminated.
2-2