Blue Reservoir Pressure is out of Tolerance

TASK 29-12-00-810-812-A
Blue Reservoir Pressure is out of Tolerance

1. Possible Causes

PRESSURE REDUCING VALVE

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Referenced Information

REFERENCE	DESIGNATION
AMM 12-32-29-281-001	Hydraulic Fluid Sample of Green, Blue and Yellow Systems for Analysis
AMM 29-00-00-864-001	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
AMM 29-14-00-720-001	Functional Test of the Pressurizing System of the Hydraulic Reservoirs
AMM 29-14-43-000-001	Removal of the Pressure Reducing Valve
AMM 29-14-43-400-001	Installation of the Pressure Reducing Valve
AMM 32-12-00-010-001	Open the Main Gear Doors for Access

3. Fault Confirmation
Subtask 29-12-00-865-058-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
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N30
123VU	B HYD/ELEC PUMP	2701GJ	AB09
123VU	Y HYD/ELEC/PUMP	3802GX	AB06
123VU	Y HYD/ELEC/ELEC PUMP/NORM	3801GX	AB03

Subtask 29-12-00-860-062-A

B. Aircraft Maintenance Configuration
(1) Depressurize the Green, Yellow and Blue hydraulic systems, but not the reservoirs AMM 29-00-00-864-001.
(2) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the hydraulic systems:

in the flight compartment on the hydraulic section 40VU of the overhead panel,
on the ground service panels of the Green, Yellow and Blue hydraulic systems.

(3) Open the access doors 196BB and 197FB.
(4) Open the right main door of the main landing gear AMM 32-12-00-010-001.
(5) Read the pressure gages (1383GM, 2383GM, 3383GM) on each hydraulic reservoir.
(6) If the reservoir pressure indication is more than 52 +2 psi or -2 psi (3.5853 +0.1379 bar or -0.1379 bar):
(a) Do the functional test of the pressurizing system of the hydraulic reservoirs AMM 29-14-00-720-001.

4. Fault Isolation
Subtask 29-12-00-810-063-A

A. If the reservoir pressure increases during the test to more than 50 +2 psi or -2 psi (3.4474 +0.1379 bar or -0.1379 bar):
(1) Replace the PRESSURE REDUCING VALVE AMM 29-14-43-000-001 and AMM 29-14-43-400-001.
(2) Take a fluid sample from each hydraulic system to make sure that the contamination of the hydraulic fluid is in the approved values AMM 12-32-29-281-001.

Subtask 29-12-00-720-050-A

B. Do the functional test of the pressurizing system of the hydraulic reservoirs again to make sure that the function is correct AMM 29-14-00-720-001.

5. Close-up
Subtask 29-12-00-865-059-A

A. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	HYD/HYD PWR/B WARN/& CTL	2702GJ	C12
121VU	HYDRAULIC/HYD POWER/Y	3803GX	N30
123VU	B HYD/ELEC PUMP	2701GJ	AB09
123VU	Y HYD/ELEC/PUMP	3802GX	AB06
123VU	Y HYD/ELEC/ELEC PUMP/NORM	3801GX	AB03

[Rev.8 from Aug 2018] 2026.04.04 04:29:22 UTC