TM 55-2840-241-23
Table 4-1. Troubleshooting (Continued)
Item
Trouble
Probable cause
Remedy
38 Continuous exhaust
smoking.
38.1 Heavy exhaust
smoking.
39 Compressor rear
bearing labyrinth
seal vent smoking.
40 Exhaust smoking on
shutdown or engine
start. (Also refer to
items 41 and 47.)
40.1 Exhaust smoking
on shutdown, or
engine start,
accompanied by
low power.
41 Static oil leakage
from burner drain
valve. (Also refer to
items 40 and 47.)
a. Compressor front
bearing oil seal leaking.
b. Power turbine oil
bellows seal leaking.
c. Internal turbine seals
leaking.
d. Oil seepage past No. 5
bearing oil bellows seal
into hot exhaust and
collector.
e. Residual oil in No. 6
and No. 7 bearing areas,
depositing on hot turbine
parts.
f. Oil leakage in aircraft
scavenge oil check valve.
Contamination or carbon
buildup in the turbine.
Seal vent orifice
improperly seated.
a. Turbine rear bearing
sump and nut assembly
leaking.
b. Faulty external oil
check valve.
Excessive clearance of
rotating knife seals
located in No. 6 and No. 7
bearing areas.
a. Faulty airframe check
valve.
b. Oil leakage from
turbine or combustion
section.
a. Replace engine if oil consumption
exceeds limit. (Refer to TM
55-1520-228-23.)
b. Replace engine.
c. Replace engine if oil consumption
exceeds limit. (Refer to TM
55-1520-228-23.)
d. After engine shutdown, check for
puddling in bottom of exhaust
collector. Replace engine if oil
consumption exceeds limits. (Refer
to TM 55-1520-228-23.)
e. Replace engine. (Refer to TM
55-1520-228-23.)
f. Replace scavenge oil check valve.
(Refer to para 5-29.)
Replace engine. (Refer to TM
55-1520-228-23.)
Replace vent orifice. (Refer to para
10-9.)
a. Replace engine if oil consumption
exceeds limit. (Refer to TM
55-1520-228-23.)
b. Clean valve (Refer to para 5-29.)
Replace engine. (Refer to to TM
55-1520-228-23.)
a. Replace valve. (Refer to TM
55-1520-228-23).
b(l). Remove and inspect the
external check valve. (Refer to para
5-29.)
b(2). Inspect for leakage from power
turbine carbon face seal.
Change 14
4-11
