Removal of the Recirculation Filter Housing

TASK 21-21-45-000-001-A
Removal of the Recirculation Filter Housing

WARNING: MAKE SURE THAT AIR IS NOT SUPPLIED TO THE AIR CONDITIONING SYSTEM FROM THE MAIN ENGINE, THE APU OR A GROUND SOURCE. HOT COMPRESSED AIR CAN CAUSE INJURY TO PERSONNEL.

ZONE: 137
FIN: 4010HM
FIN: 4011HM

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

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
FOR [4010HM] (RECIRC FILTER HOUSING 1)
No specific	AR	PLUG - BLANKING
FOR [4011HM] (RECIRC FILTER HOUSING 2)
No specific	AR	PLUG - BLANKING

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
137	BAY BETW AFT PART. BULKHEAD OF FWD CARGO
825

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-21-41-000-001-A	Removal of the Recirculation Filter Cartridge
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
Recirculation Filter Housing
FOR [4010HM] (RECIRC FILTER HOUSING 1)
TASK 25-54-12-000-001-A	Removal of the Forward Cargo-Compartment Partition
TASK 06-41-53-00	FUSELAGE-DESCRIPTION AND OPERATION
FOR [4011HM] (RECIRC FILTER HOUSING 2)
TASK 25-54-12-000-001-A	Removal of the Forward Cargo-Compartment Partition
TASK 06-41-53-00	FUSELAGE-DESCRIPTION AND OPERATION

3. Job Set-up
Subtask 21-21-45-861-050-A

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 21-21-45-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4010HM (RECIRC FILTER HOUSING 1)
122VU	AIR COND/RECIRC FAN/L/CTL	2HG	X20
122VU	AIR COND/RECIRC FAN/L/SPLY	1HG	X18
FOR FIN: 4011HM (RECIRC FILTER HOUSING 2)
122VU	AIR COND/RECIRC FAN/R/CTL	11HG	W20
122VU	AIR COND/RECIRC FAN/R/SPLY	3HG	W18

Subtask 21-21-45-941-050-A

C. Safety Precautions
(1) On the AIR COND panel 30VU:
(a) Make sure that the APU BLEED pushbutton switch is released (the ON legend is off).
(b) Make sure that the ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are released (the OFF legends are on).
(c) Put a WARNING NOTICE(S) in position to tell persons not to operate these pushbutton switches.
(2) On the HP and the LP ground connectors:
(a) Put a WARNING NOTICE(S) in position to tell persons not to supply air from a ground air source.

Subtask 21-21-45-010-050-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the FWD cargo-compartment door 825 (Ref. AMM TASK 52-30-00-860-001).
(2) Put the ACCESS PLATFORM 2M (6 FT) in position at the FWD cargo-compartment door 825.
(3) FOR [4010HM] (RECIRC FILTER HOUSING 1)

Remove the left-forward cargo-compartment partition at FR34 (Ref. AMM D/O 06-41-53-00) (Ref. AMM TASK 25-54-12-000-001).

(4) FOR [4011HM] (RECIRC FILTER HOUSING 2)

Remove the right-forward cargo-compartment partition at FR34 (Ref. AMM D/O 06-41-53-00) (Ref. AMM TASK 25-54-12-000-001).

Subtask 21-21-45-010-050-B ** ON A/C NOT FOR ALL

Remove the left-forward cargo-compartment partition at FR35.7 (Ref. AMM D/O 06-41-53-00) (Ref. AMM TASK 25-54-12-000-001).

(4) FOR [4011HM] (RECIRC FILTER HOUSING 2)

Remove the right-forward cargo-compartment partition at FR35.7 (Ref. AMM D/O 06-41-53-00) (Ref. AMM TASK 25-54-12-000-001).

Subtask 21-21-45-020-050-A

E. Remove the related recirculation filter (Ref. AMM TASK 21-21-41-000-001).

4. Procedure
Subtask 21-21-45-020-051-A

A. Removal of the Recirculation Filter Housing
(1) FOR [4010HM] (RECIRC FILTER HOUSING 1)
(a) Loosen the clamp (11).
(b) Remove the tube (10) with the clamp (11) from the recirculation filter housing (1).
(c) Remove the two bolts (5) and the two washers (4) from the supports (2) and (3) and the recirculation filter housing (1).
(d) Remove the two bolts (6) and the two washers (7) from the support (3) and the recirculation filter housing (1).
(e) Remove the two nuts (13), the two washers (12), the two bolts (8) and the two washers (9) from the support (3) and the recirculation filter housing (1).
(f) Remove the two bolts (16) and the two washers (15) from the support (14) and the recirculation filter housing (1).
(g) Remove the recirculation filter housing (1).
(h) Put a PLUG - BLANKING on the disconnected line end(s).
(2) FOR [4011HM] (RECIRC FILTER HOUSING 2)
(a) Remove the four bolts (20) and the four washers (19) from the support (21) and the recirculation filter housing (18).
(b) Remove the three bolts (23) and the three washers (22) from the recirculation filter housing (18) and the support (26).
(c) Remove the three bolts (24) and the three washers (25) from the recirculation filter housing (18) and the support (26).
(d) Remove the three nuts (29), the three washers (30), the three bolts (34) and the three washers (33) from the support (26) and the recirculation filter housing (18).
(e) Remove the three nuts (27), the three washers (28), the three bolts (31) and the three washers (32) from the support (26) and the recirculation filter housing (18).
(f) Remove the four bolts (37) and the four washers (36) from the support (17) and the recirculation filter housing (18).
(g) Remove the recirculation filter housing (18).
(h) Put a PLUG - BLANKING on the disconnected line end(s).

[Rev.10 from 2021] 2026.04.02 06:58:57 UTC