Fumes in the Cabin/Oil Smoke at the APU Exhaust (APS 3200)

TASK 49-00-00-810-921-A
Fumes in the Cabin/Oil Smoke at the APU Exhaust (APS 3200)

1. Possible Causes

plumbing
PMG and COOLING FAN ASSEMBLY (8055KM)
OIL COOLER
oil pump assembly
oil filler cap and scupper
pressure fill and overflow ports
GEN-APU 8XS
SWITCH-LOP [8091KM]
APU [4005KM]
AUXILIARY POWER UNIT 4005KM
unwanted material in the internal areas of the air inlet duct, the air intake diffuser and elbow
flexible seals on the air intake system
alignment of the air inlet duct

2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
No specific	overflow drain tool

B. Referenced Information

REFERENCE	DESIGNATION
AMM 12-33-21-618-001	Pre-conditioning through the LP Ground Connection
AMM 21-00-00-615-001	Decontamination of the Environmental Control System (ECS) when the Temperature is below 24 deg.C (APU)
AMM 21-00-00-615-002	Decontamination of the Environmental Control System (ECS) when the Temperature is above 24 deg.C (APU)
AMM 21-00-00-615-003	Decontamination of the Environmental Control System (ECS) when the Temperature is below 24 deg.C (Engine/s)
AMM 21-00-00-615-004	Decontamination of the Environmental Control System (ECS) when the Temperature is above 24 deg.C (Engine/s)
AMM 24-23-51-000-001	Removal of the APU Generator
AMM 24-23-51-400-001	Installation of the APU Generator
AMM 49-00-00-100-002	Cleaning of the APU Compartment with installed APU
AMM 49-00-00-790-007	Check APU Compartment and Air Intake Duct for Oil Contamination (APS 3200)
AMM 49-11-11-000-003	Removal of the Power Plant (APU) (APS 3200)
AMM 49-11-11-400-003	Installation of the Power Plant (APU) (APS 3200)
AMM 49-16-00-100-004	Cleaning of the APU Air Intake (GTCP 36-300)
AMM 49-16-00-210-002	Detailed Inspection of APU Air Intake, Diffuser Elbow, Seals and Felt Metal (APS 3200)
AMM 49-20-00-290-001	APU Power Plant Borescope Inspection (APS 3200)
AMM 49-52-53-000-001	Removal of the PMG and Cooling Fan Assembly (APS 3200)
AMM 49-52-53-400-001	Installation of the PMG and Cooling Fan Assembly (APS 3200)
AMM 49-90-00-600-004	Check Oil Level and Replenish (APS 3200)
AMM 49-91-44-000-003	Removal of the Oil Cooler (APS 3200)
AMM 49-91-44-400-003	Installation of the Oil Cooler (APS 3200)
AMM 49-94-14-000-002	Removal of the Oil Pressure Switch (APS 3200)
AMM 49-94-14-400-002	Installation of the Oil Pressure Switch (APS 3200)

3. Fault Confirmation
Subtask 49-00-00-710-282-A ** ON A/C NOT FOR ALL

A. Do the pre-conditioning with the APU AMM 12-33-21-618-001.

4. Fault Isolation
Subtask 49-00-00-810-168-A ** ON A/C NOT FOR ALL

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

A. If you smell fumes in the cabin during the pre-conditioning with the APU:

do a check for signs of oil, fuel and other unwanted material on the internal areas of the air inlet duct and the air intake diffuser and elbow,
do a check for signs of oil and/or fuel on the external areas and the flexible seals on the air intake diffuser and elbow,
do a check for signs of oil and/or fuel in the APU access doors.

(1) If you find signs of oil and/or fuel in the external and/or the internal areas of the air inlet duct, the air intake diffuser and elbow and/or the APU access doors:

follow the signs of the oil and/or fuel and check the external of the APU in that area for leaks from there the oil and/or fuel came AMM 49-00-00-790-007.

NOTE: Do the check very carefully on the:

plumbing ,
PMG and COOLING FAN ASSEMBLY (8055KM),
OIL COOLER ,
oil pump assembly ,
oil filler cap and scupper ,
pressure fill and overflow ports ,
GEN-APU 8XS
SWITCH-LOP [8091KM]

(a) If you find a leak on the plumbing:

do the repair and replace the tubes, connectors and packings as necessary.

(b) If you find leak oil in the area of the PMG and cooling fan assembly:

replace the PMG and COOLING FAN ASSEMBLY AMM 49-52-53-000-001 and AMM 49-52-53-400-001.

replace the OIL COOLER AMM 49-91-44-000-003 and AMM 49-91-44-400-003 and/or the packings of the oil line connectors as necessary.

(d) If you find that the oil filler cap is not tight:

make sure that the oil level in the oil reservoir is not more than the FULL mark on the sight glass and correct it with the overflow drain tool if necessary AMM 49-90-00-600-004.
make sure that the oil filler cap and the packing are in the correct condition and replace them if necessary,
make sure that the oil scupper packing seals correctly and replace if it necessary.

(e) If you find that the valves of the pressure fill and overflow ports are not tight:

replace the valves as necessary.

(f) If you find leak oil in the area of the oil pump assy:

replace the packings as necessary or replace the APU [4005KM] .

(g) If you find leak oil in the area of the APU generator:

replace the GEN-APU 8XS and/or the SEALING PLATE as necessary AMM 24-23-51-000-001 and AMM 24-23-51-400-001.

(h) If you find leak oil in the area of the oil cooler:

replace the SWITCH-LOP [8091KM] AMM 49-94-14-000-002 and AMM 49-94-14-400-002 and/or the packings of the oil line connectors as necessary.

(i) If the fault continues:

replace the AUXILIARY POWER UNIT 4005KM AMM 49-11-11-000-003 and AMM 49-11-11-400-003.

(2) If you find other unwanted material in the internal areas of the air inlet duct, the air intake diffuser and elbow:

make sure what material it is and where it came from,
if you think that the unwanted material has damaged the APU compressors, do the boroscope inspection of the compressors AMM 49-20-00-290-001.

(a) If the fault continues:

replace the APU [4005KM] AMM 49-11-11-000-003 and AMM 49-11-11-400-003.

Subtask 49-00-00-810-169-A ** ON A/C NOT FOR ALL

B. If you see oil smoke at the exhaust during the operation of the APU:

replace the APU APU [4005KM] AMM 49-11-11-000-003 and AMM 49-11-11-400-003.

Subtask 49-00-00-810-170-A ** ON A/C NOT FOR ALL

C. Cleaning and Testing

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

(1) Clean the APU AMM 49-00-00-100-002,
(2) Make sure that:

the flexible seals on the air intake system are in the correct condition
the alignment of the air inlet duct is correct
AMM 49-16-00-210-002.

(3) Clean the air inlet duct and the air intake diffuser and elbow AMM 49-16-00-100-004,
(4) Clean the APU bleed air duct, the pneumatic ducts of the aircraft and the environmental control system AMM 21-00-00-615-001 or AMM 21-00-00-615-002 and AMM 21-00-00-615-003 or AMM 21-00-00-615-004.
(5) Do the pre-conditioning with the APU AMM 12-33-21-618-001 and make sure that you do not smell fumes in the cabin and/or see oil smoke at the APU exhaust.
(6) Do a check and make sure that you do not find an oil leak on the APU, the APU generator and check for Oil leak at the Oil Press SW (8091KM).

[Rev.8 from Aug 2018] 2026.04.04 04:34:26 UTC