TM 5-4520-256-14
3-9. TROUBLESHOOTING - Continued.
Table 3-2. Unit Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
4.
LOW FUEL PRESSURE.
Step 1.
Check fuel tank for fuel.
If fuel tank has improper amount of fuel, add fuel.
If fuel tank has proper amount of fuel, proceed to step 2.
Step 2.
Check that INTERNAL TANK/EXTERNAL TANK selector switch is set for proper tank being used.
If selector switch is improperly set, correctly set switch.
If selector switch is properly set, proceed to step 3.
Step 3.
Check fuel line for leaks or kinks.
If fuel line is kinked, remove kink.
If fuel line leaks, repair or replace fuel line (para 3-33).
If fuel line is not leaking or kinked, proceed to step 4.
Step 4.
Check for jammed or damaged EXTERNAL TANK/INTERNAL TANK selector valve.
If valve does not rotate freely, replace valve (para 3-22).
If valve does not rotate freely, proceed to step 5.
Step 5.
Check for moisture, frost, or ice in lines or fuel filter. Check fuel filter for clogging or extreme
dirtiness.
If fuel has frost or ice, drain fuel lines.
If fuel filter is clogged or dirty, clean filter (para 3-35).
If moisture, ice, or dirt is not present, proceed to step 6.
Step 6.
Check solenoid valve (L1) for leaks or defects.
If valve leaks or is defective, replace valve (para 3-34).
If valve does not leak or is not defective, proceed to step 7.
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