Removal of the Oil Filler Cap

TASK 49-91-48-000-801-A
Removal of the Oil Filler Cap

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

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 4M (13 FT)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)

B. Referenced Information

REFERENCE	DESIGNATION
TASK 12-32-49-281-001-A	Oil Sampling for Analysis
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 49-91-42-000-003-A	Removal of the Drain Plug (131-9(A))
TASK 49-91-42-400-003-A	Installation of the Drain Plug (131-9(A))
TASK 52-41-00-010-001-A	Open the APU Doors for Access
Oil Filler Cap

3. Job Set-up
Subtask 49-91-48-860-050-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) On the panel 25VU, make sure that the APU MASTER SW p/bsw is OFF.
(3) Put a WARNING NOTICE(S) in the cockpit to tell persons not to start the APU.
(4) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).

Subtask 49-91-48-865-050-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-91-48-010-050-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT) in position below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL, 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set LIGHT control switch 11LJ to the ON position.

Subtask 49-91-48-680-050-A ** ON A/C NOT FOR ALL

WARNING: BE CAREFUL WHEN YOU DRAIN THE ENGINE OIL AND/OR LOOSEN THE FILLER CAP. HOT OIL CAN SPILL PAST THE FILLER CAP WHEN THE OIL LEVEL IS ABOVE THE 'ADD' RANGE (MARKED ON THE SIGHT GLASS).

WARNING: USE THE CORRECT PERSONAL PROTECTION. OIL CAN HAVE ADDITIVE CALLED TRICRESYL PHOSPHATE IN IT. THIS CHEMICAL IS AN ASPHYXIANT, IT IS POISONOUS AND CAN BE ABSORBED THROUGH THE SKIN. USE CARE WHEN ENGINE OIL IS DRAINED. HOT OIL CAN POSSIBLY CAUSE BAD BURNS.

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

D. Oil Drainage

NOTE: Do the Oil level inspection check and servicing a minimum of 15 minutes after the last shutdown. More servicing is not permitted before the APU is operated again.

(1) Open the oil filler cap (1).
(a) Pull the lock and slowly open the oil filler cap (1) to release pressure from the APU.
(2) Remove the drain plug (Ref. AMM TASK 49-91-42-000-003).
(3) If you think that the condition of the drained oil is not correct, get a sample of the APU oil for analysis (Ref. AMM TASK 12-32-49-281-001).
(4) Install the drain plug (Ref. AMM TASK 49-91-42-400-003).

4. Procedure
Subtask 49-91-48-000-050-A ** ON A/C NOT FOR ALL

A. Removal of the Oil Filler Cap
(1) Remove the nut (9), the bracket (8), the bolt (6) and the washer (7).
(2) Remove the oil filler cap (1).
(3) If necessary, remove the nut (2), the bolt (5), the washers (3) and the roller (4).

[Rev.10 from 2021] 2026.04.01 01:33:37 UTC