Removal of the Reservoir Pressure Check Valves

TASK 29-14-18-000-001-A
Removal of the Reservoir Pressure Check Valves

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

FIN: 1388GM
FIN: 2388GM
FIN: 3388GM

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	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Referenced Information

REFERENCE	DESIGNATION
TASK 25-21-41-000-001-A	Removal of the Passenger Seats
TASK 25-55-11-000-001-A	Removal of the Aft Cargo-Compartment Partition at FR47
TASK 25-55-11-000-002-A	Removal of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 25-55-11-000-003-A	Removal of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59
TASK 28-11-27-000-001-A	Removal of the Additional Center Tank (ACT)
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 53-32-12-000-002-A	Removal of the Cabin Floor Panels
TASK 53-42-12-000-001-A	Removal of the Cabin Floor Panels from FR47 thru FR64
Reservoir Check Valves ** ON A/C NOT FOR ALL
Reservoir Check Valves ** ON A/C NOT FOR ALL
Reservoir Check Valves ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 29-14-18-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	HYD/HYD PWR/B WARN/& CTL	2702GJ	C12
** ON A/C NOT FOR ALL
49VU	HYDRAULIC/G HYD/PUMP ENG1/CTL	1701GK	H12
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/G HYD/PUMP ENG1/CTL	1701GK	R35
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N30
121VU	HYDRAULIC/G HYD/PUMP ENG1/MONG	1702GK	R34
** ON A/C ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41
** ON A/C NOT FOR ALL
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N31
121VU	HYDRAULIC/G HYD/PUMP ENG1/MONG	1702GK	R33
** ON A/C ALL
123VU	B HYD/ELEC PUMP	2701GJ	AB09
123VU	Y HYD/ELEC/PUMP	3802GX	AB06
123VU	Y HYD/ELEC/ELEC PUMP/NORM	3801GX	AB03

Subtask 29-14-18-860-050-B ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) For 1388GM:
(a) Put the warning notices in position on the panels that follow, to tell persons not to pressurize the Green hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel
On the ground service panel of the Green hydraulic system.

(b) Make sure that the Green hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(c) Depressurize the reservoir of the Green hydraulic system
(Ref. AMM TASK 29-14-00-614-001).
(d) Remove the applicable passenger seats to get access to the floor panel between FR42 and FR43, if necessary (Ref. AMM TASK 25-21-41-000-001).
(e) Remove the floor panel between FR42 and FR43 (Ref. AMM TASK 53-32-12-000-002).
(2) For 2388GM:
(a) Put the warning notices in position to tell persons not to pressurize the Blue hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel
On the ground service panel of the Blue hydraulic system.

(b) Make sure that the Blue hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(c) Depressurize the reservoir of the Blue hydraulic system.
(Ref. AMM TASK 29-14-00-614-001).
(d) Get access to 2388GM from the aft cargo compartment:
1 Remove the ceiling panel between FR47 and FR50 (Ref. AMM TASK 25-55-11-000-002).
2 If necessary, remove the sidewall panel(s) between FR47 and FR50 (Ref. AMM TASK 25-55-11-000-003).
3 If necessary, remove the partition panel(s) between FR47 and FR50 (Ref. AMM TASK 25-55-11-000-001).

or

(e) Get access to 2388GM from the passenger compartment:
1 Remove the applicable passenger seats to get access to the floor panel between FR47 and FR51, if necessary (Ref. AMM TASK 25-21-41-000-001).
2 Remove the floor panel between FR47 and FR51 (Ref. AMM TASK 53-42-12-000-001).
(3) For 3388GM:
(a) Put the warning notices in position to tell persons not to pressurize the Yellow hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel
On the ground service panel of the Yellow hydraulic system.

(b) Make sure that the Yellow hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(c) Depressurize the reservoir of the Yellow hydraulic system.
(Ref. AMM TASK 29-14-00-614-001).
(d) Remove the applicable passenger seats to get access to the floor panel between FR42 and FR43, if necessary (Ref. AMM TASK 25-21-41-000-001).
(e) Remove the floor panel between FR42 and FR43 (Ref. AMM TASK 53-32-12-000-002).

Subtask 29-14-18-860-050-C ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) For 1388GM
(a) Put the warning notices in position to tell persons not to pressurize the Green hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel,
On the ground service panel of the Green hydraulic system.

(b) Make sure that the Green hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001)
(c) Depressurize the reservoir of the Green hydraulic system
(Ref. AMM TASK 29-14-00-614-001).
(d) Remove the applicable passenger seats to get access to the floor panel between FR42 and FR43, if necessary (Ref. AMM TASK 25-21-41-000-001).
(e) Remove the floor panel between FR42 and FR43 (Ref. AMM TASK 53-32-12-000-002).
(2) For 2388GM
(a) Put the warning notices in position to tell persons not to pressurize the Blue hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel,
On the ground service panel of the Blue hydraulic system.

(b) Make sure that the Blue hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001)
(c) Depressurize the reservoir of the Blue hydraulic system.
(Ref. AMM TASK 29-14-00-614-001).
(d) Get access to 2388GM from the aft cargo compartment:
1 Remove the ceiling panel between FR47/51 and FR54 (Ref. AMM TASK 25-55-11-000-002).

or

(e) Get access to 2388GM from the passenger compartment:
1 Remove the applicable passenger seats to get access to the floor panel between FR47/51 and FR54, if necessary (Ref. AMM TASK 25-21-41-000-001).
2 Remove the floor panel between FR47/51 and FR54 (Ref. AMM TASK 53-42-12-000-001).
(3) For 3388GM
(a) Put the warning notices in position to tell persons not to pressurize the Yellow hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel,
On the ground service panel of the Yellow hydraulic system.

(b) Make sure that the Yellow hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001)
(c) Depressurize the reservoir of the Yellow hydraulic system.
(Ref. AMM TASK 29-14-00-614-001).
(d) Remove the applicable passenger seats to get access to the floor panel between FR42 and FR43, if necessary (Ref. AMM TASK 25-21-41-000-001).
(e) Remove the floor panel between FR42 and FR43 (Ref. AMM TASK 53-32-12-000-002).

Subtask 29-14-18-860-050-E ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) For 1388GM
(a) Put the warning notices in position on the panels that follow to tell persons not to pressurize the Green hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel
On the ground service panel of the Green hydraulic system.

(b) Make sure that the Green hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(c) Depressurize the reservoir of the Green hydraulic system
(Ref. AMM TASK 29-14-00-614-001).
(d) Remove the applicable passenger seats to get access to the floor panel between FR42 and FR43, if necessary (Ref. AMM TASK 25-21-41-000-001).
(e) Remove the floor panel between FR42 and FR43 (Ref. AMM TASK 53-32-12-000-002).
(2) For 2388GM
(a) Put the warning notices in position to tell persons not to pressurize the Blue hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel
On the ground service panel of the Blue hydraulic system.

(b) Make sure that the Blue hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(c) Depressurize the reservoir of the Blue hydraulic system.
(Ref. AMM TASK 29-14-00-614-001).
(d) Get access to 2388GM from the aft cargo compartment:
1 Remove the additional center tank(s), if installed (Ref. AMM TASK 28-11-27-000-001).
2 Remove the ceiling panel between FR47 and FR47.5 (Ref. AMM TASK 25-55-11-000-002).
3 If necessary, remove the sidewall panel(s) between FR47 and FR47.5 (Ref. AMM TASK 25-55-11-000-003).
4 If necessary, remove the partition panel(s) between FR47 and FR47.5 (Ref. AMM TASK 25-55-11-000-001).

or

(e) Get access to 2388GM from the passenger compartment:
1 Remove the applicable passenger seats to get access to the floor panel between FR47 and FR47.5, if necessary (Ref. AMM TASK 25-21-41-000-001).
2 Remove the floor panel between FR47 and FR47.5 (Ref. AMM TASK 53-42-12-000-001).
(3) For 3388GM
(a) Put the warning notices in position to tell persons not to pressurize the Yellow hydraulic system:

In the cockpit on the hydraulic section 40VU of the overhead panel
On the ground service panel of the Yellow hydraulic system.

4. Procedure
Subtask 29-14-18-020-050-B

A. Removal of the Reservoir Pressure Check Valves

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT HYDRAULIC LINES ON UNIONS. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL LOOSEN OR TIGHTEN THE UNION TOO MUCH.

(1) Remove and discard the lockwire from the check valve (2) (only (1388GM), (3388GM)).
(2) Loosen the union nut (3) and disconnect the air bleed pipe from the check valve (2).
(3) Install a PLUG - BLANKING in the open pipe end.
(4) Remove the check valve (2).
(5) Install a PLUG - BLANKING in the open port.
(6) Remove and discard the O-ring (1) from the check valve (2).

[Rev.10 from 2021] 2026.04.01 08:09:20 UTC