Table 3-1 lists the common fault conditions that may be found during the operation or maintenance of the
equipment. Look for causes and do corrective actions in the order listed. This manual cannot list every
symptom that may show up, and it cannot list all of the possible causes and corrective actions. If a symptom is
not listed, or if it keeps up after you have performed the corrective actions, notify your supervisor.
Table 3-1. Troubleshooting
TEST OR INSPECTION
Coolant loss (internal).
Check if lubricating oil cooler is leaking.
Isolate elements and pressure test for air leaks. Refer to para. 3-17.
Lube oil pressure too low.
Check if main oil pressure regulator is malfunctioning.
Repair main oil pressure regulator assembly. Refer to para. 3-15.
Check if oil cooler bypass valve is malfunctioning.
Repair oil cooler bypass valve assembly. Refer to para. 3-15.
Check if oil cooler is plugged.
Repair oil cooler elements. Refer to para. 3-17.
Check if there is internal engine damaged.
Analyze the lubricating oil. Refer to LO 55-1905-223-12.
Check if lubricating oil pump is malfunctioning.
Replace lubricating oil pump. Refer to para. 3-23.
Check if oil pressure gauge is malfunctioning.
Check gauge against one of known accuracy.
Lube oil temperature too high.
Check if oil cooler by-pass valve is malfunctioning.
Repair the oil cooler by-pass valve assembly. Refer to para. 3-15.
Lube oil in coolant or coolant in lube oil.
Check if lubricating oil cooler is malfunctioning.
Replace oil cooler. Refer to para. 3-17.