Drain Mast Leakage Identification Procedure with Engine Motoring [CFMB]

TASK 71-00-00-790-811-A
Drain Mast Leakage Identification Procedure with Engine Motoring

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) - ADJUSTABLE
No specific	AR	BOTTLE - PLASTIC

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-790-002-B	Fuel or Hydraulic or Oil Leakage Limits
TASK 71-13-00-010-040-B	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-B	Closing of the Fan Cowl Doors
TASK 73-29-00-710-040-B	Operational Test of the FADEC on the Ground (with Engine Motoring)
TASK 73-29-00-710-040-B-02	Operational Test of the FADEC on the Ground (with Engine Non motoring)
TASK 78-30-00-081-041-B	Make the Thrust Reverser Serviceable after Maintenance
TASK 78-30-00-481-041-B	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-36-00-010-040-B	Opening of the Thrust Reverser Doors
TASK 78-36-00-410-040-B	Closing of the Thrust Reverser Doors
TASK 71-70-00-00-06	POWER PLANT DRAINS - DESCRIPTION AND OPERATION

3. Job Set-up
Subtask 71-00-00-010-214-A ** ON A/C NOT FOR ALL

Subtask 71-00-00-040-116-A ** ON A/C NOT FOR ALL

B. Make the thrust reverser unserviceable (Ref. AMM TASK 78-30-00-481-041).

Subtask 71-00-00-010-215-A ** ON A/C NOT FOR ALL

C. Open the thrust reverser doors (Ref. AMM TASK 78-36-00-010-040):
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 71-00-00-869-413-A ** ON A/C NOT FOR ALL

D. Prepare for Test
(1) For source identification of a fuel leak at the drain mast:
(a) Install the BOTTLE - PLASTIC and tubes on all possible fuel leakage sources (Ref. AMM D/O 71-70-00-00).

NOTE: For identification of a static fuel leak, the Variable Bleed Valve (VBV) gear motor must be disconnected first (this is the more likely accessory to be suspect).

(2) For source identification of an oil leak at the drain mast:
(a) Install the BOTTLE - PLASTIC and tubes on all possible oil leakage sources (Ref. AMM D/O 71-70-00-00).

Subtask 71-00-00-410-198-A ** ON A/C NOT FOR ALL

E. Close Access
(1) Close the thrust reverser doors (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR
(2) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR

4. Procedure
Subtask 71-00-00-790-073-A ** ON A/C NOT FOR ALL

A. To Identify the Source of the Leak at the Drain Mast
(1) To check for fuel leaks at the drain mast, do the following steps:
(a) Do a operational test of the FADEC on the ground (with engine motoring) (Ref. AMM TASK 73-29-00-710-040).
(2) Measure the individual leakage quantities collected from each plastic bottle. For the fuel, oil and hydraulic fluid leakage limits (Ref. AMM TASK 71-00-00-790-002).

5. Close-up
Subtask 71-00-00-010-216-A ** ON A/C NOT FOR ALL

A. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(3) Open the thrust reverser doors (Ref. AMM TASK 78-36-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 71-00-00-869-414-A ** ON A/C NOT FOR ALL

B. Reconnect drain lines
(1) Remove the plastic bottles and tubes.
(2) Reconnect the drain lines.

Subtask 71-00-00-410-199-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser doors (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 71-00-00-440-109-A ** ON A/C NOT FOR ALL

D. Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-081-041).

Subtask 71-00-00-410-200-A ** ON A/C NOT FOR ALL

E. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the access platform(s).

[Rev.10 from 2021] 2026.04.02 06:32:14 UTC