Yellow Hydraulic System Noise More Than Usual

TASK 29-13-00-810-820-A
Yellow Hydraulic System Noise More Than Usual

1. Possible Causes

incorrectly installed hydraulic pipes (forced installation)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 29-00-00-210-003	Detailed Visual Inspection for Correct Installation of the Green and Yellow System Hydraulic Pipes in the MLG Bay
AMM 29-13-00-710-002	Operational Test of the Yellow Hydraulic System
AMM 71-00-00-860-814	Shutdown of the Engine
AMM 71-00-00-860-823	Start the Engine (Normal Automatic Start)

3. Fault Confirmation
Subtask 29-13-00-700-051-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational test of the Yellow hydraulic system AMM 29-13-00-710-002:
(a) If there is more noise than usual from the Yellow hydraulic system:
(b) Do the Fault Isolation.

NOTE: Noise in the Yellow hydraulic system can be caused by incorrectly installed hydraulic pipes (forced installation) and/or damaged clamps.

Subtask 29-13-00-700-051-B ** ON A/C NOT FOR ALL

A. Do a Check of the Entries in Logbook
(1) If you find one or more of the following conditions, no further trouble shooting is necessary:
(a) Noise is identified between seat rows 9 to 18.
(b) Noise is reported constantly with no level variation.
(c) The noise is reported all along the flight (from engine start, flight phases to engine stop).
(2) If you find other noises, it is necessary to do the related trouble shooting procedure.

4. Fault Isolation
Subtask 29-13-00-810-076-A ** ON A/C NOT FOR ALL

Subtask 29-13-00-810-076-B ** ON A/C NOT FOR ALL

A. Procedure
(1) Do the detailed visual inspection for correct installation of Green and Yellow system hydraulic pipes in the MLG bay AMM 29-00-00-210-003:
(a) Repair the defects found.
(b) Do the operational test of the Yellow hydraulic system AMM 29-13-00-710-002.
(2) If you cannot identify the location and/or characteristics of the noise, do the steps that follow:
(a) Do an automatic start of engine 1 AMM 71-00-00-860-823.
(b) Make sure that you hear the noise.
(c) Depressurize G EDP from 40VU panel and set PTU to off.
(d) Make sure that you cannot hear the reported noise in the cabin.
(e) Stop the engine 1 AMM 71-00-00-860-814.
(f) Do an automatic start of engine 2 AMM 71-00-00-860-823.
(g) Make sure that you hear the noise.
(h) Depressurize Y EDP from 40VU panel and set PTU to off.
(i) Make sure that you cannot hear the reported noise in the cabin.
(j) Stop the engine 2 AMM 71-00-00-860-814.

[Rev.8 from Aug 2018] 2026.04.04 04:29:27 UTC