Drain Mast Leakage Identification Procedure [CFML]

TASK 71-00-00-790-806-A
Drain Mast Leakage Identification Procedure

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

1. Reason for the Job
A. This task tells which engine components are connected to the holes in the fan drain mast and the core drain mast.
B. If a leak occurs at a drain mast occurs, this task can help identify the component that caused the leak.
C. Refer to AMM Task 71-00-00-790-805 for fuel or hydraulic or oil leakage limits.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	CAP - PROTECTION
No specific	AR	COVER - PROTECTION
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-790-805-A	Fuel or Hydraulic or Oil Leakage Limits
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 72-24-01-000-801-A	Removal of Segment Shrouds 1 thru 5
TASK 72-24-01-400-801-A	Installation of Segment Shrouds 1 thru 5
TASK 78-30-00-040-807-A	Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU)
TASK 78-30-00-440-807-A	Reactivation of the Thrust Reverser System after Nacelle Maintenance (ICU)
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
Fan Drain Mast Leakage Identification
Core Drain Mast Leakage Identification

3. Job Set-up
Subtask 71-00-00-941-156-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 71-00-00-010-203-A

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR

Subtask 71-00-00-040-112-A

C. Deactivation of the Thrust Reverser System

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for nacelle maintenance (ICU) (Ref. AMM TASK 78-30-00-040-807).

Subtask 71-00-00-010-204-A

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.

4. Procedure
Subtask 71-00-00-210-110-A

A. Visual Inspection of the Fan Drain Mast for Leakage

Fan Drain Mast Leakage Identification

(1) Refer to (Ref. AMM TASK 71-00-00-790-805) for fuel or hydraulic or oil leakage limits.
(a) Each of the five holes in the fan drain mast are directly connected to one component. If you see leakage at a drain hole, the leak is caused by the related component. Each drain hole is identified by the component connected to it:

Engine Driven Pump (EDP) drain
Integrated Drive Generator (IDG) drain
Hand crank drain
Oil tank overfill drain
Fuel pump drain.

Subtask 71-00-00-210-111-A

B. Visual Inspection of the Core Drain Mast for Leakage

Core Drain Mast Leakage Identification

(1) Four of the six holes in the core drain mast are directly connected to one component. If you see leakage from the holes that follow, the leak is caused by the related component:

A-sump drain
B-sump drain
Pylon fuel
Pylon C zone.

NOTE: The drain hole for the pylon Left Hand (LH) side drain is on the side of the core drain mast. The other five holes are in the bottom of the core drain mast.

(2) The components that follow are connected to the drain hole identified as the engine Right Hand (RH) side drain:

Transient Bleed Valve (TBV) drain
Right Variable Bleed Valve (VBV) actuator drain
Start bleed valve-booster anti-ice valve drain
Right Variable Stator Vane (VSV) actuator drain
Right modulated turbine cooling valve actuator drain.

(3) If leakage occurs at the engine RH side drain port, do the following steps to identify the component that caused the leakage, as follows:

NOTE: Only fuel components drain to this port.

(a) Disconnect the R4 coupling nut from the drain for the modulated turbine cooling valve actuator.
(b) Remove the drain line from the R4 coupling nut and R5 coupling nut.
(c) Disconnect the R5 coupling nut from the drain for the VSV actuator.
(d) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the modulated turbine cooling valve actuator. Fluid in this container will come from the modulated turbine cooling valve actuator.
(e) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the VSV actuator drain. Fluid in this container will come from the right VSV actuator.
(f) Disconnect the R1 coupling nut from the drain port on the TBV.
(g) Loosen the P-clamp by hand.
(h) Install a CONTAINER 10 L(2 1/2 USGAL) on the drain port on the TBV. Fluid in this container will come from the TBV.
(i) Disconnect the R2 coupling nut from the drain for the start bleed valve-booster anti-ice valve.
(j) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the start bleed valve-booster anti-ice valve. Fluid in this container will come from the start bleed valve-booster anti-ice valve.
(k) Disconnect the R7A coupling nut from the drain for the VBV actuator.
(l) Remove two P-clamps from the engine.
(m) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the VBV actuator. Fluid in this container will come from the VBV actuator.
(n) Install CAP - PROTECTION and COVER - PROTECTION on all the open tubes and ports that are not used during the leak check.
(o) Close the thrust reverser doors (Ref. AMM TASK 78-36-00-410-806).
(p) Do an engine run at idle as per (Ref. AMM TASK 71-00-00-790-805) for fuel or hydraulic or oil leakage limits.
(q) Open the thrust reverser doors (Ref. AMM TASK 78-36-00-010-806).
(4) When the cause of the leak has been identified, do the steps that follow:
(a) Remove the CAP - PROTECTION and COVER - PROTECTION from the tubes and ports immediately before you connect the applicable components.
(b) Remove all the CONTAINER 10 L(2 1/2 USGAL) from the engine.
(c) Install the drain line with the R4 coupling nut and the R5 coupling nut.
(d) Connect the R4 coupling nut to the drain for the modulated turbine cooling valve actuator.
(e) TORQUE the R4 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(f) Connect the R5 coupling nut to the drain for the VSV actuator.
(g) TORQUE the R5 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(h) Connect the R1 coupling nut to the drain port for the TBV.
(i) TORQUE the R1 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(j) Connect the R2 coupling nut to the drain for the start bleed valve-booster anti-ice valve.
(k) TORQUE the R2 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(l) Connect the R7A coupling nut to the drain for the VBV actuator.
(m) Install the two P-clamps to the drain.
(n) TORQUE the R7A coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(5) The components that follow are connected to the drain hole identified as the engine LH side drain:

High Pressure Turbine Active Clearance Control (HPTACC) valve
Low Pressure Turbine Active Clearance Control (LPTACC) valve
Left VBV actuator drain
Left VSV actuator drain
Left modulated turbine cooling valve actuator drain.

(6) If a leak occurs at the LH side drain port, do the following steps to identify the component that caused the leak, as follows:

NOTE: Only fuel components drain to this port.

(a) Disconnect the L5 coupling nut from the drain for the HPTACC valve.
(b) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the HPTACC valve. Fluid in this container will come from the HPTACC valve.
(c) Disconnect the L6 coupling nut from the drain for the LPTACC valve.
(d) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the LPTACC valve. Fluid in this container will come from the LPTACC valve.
(e) Remove the engine kit segment shroud 5 (Ref. AMM TASK 72-24-01-000-801).
(f) Disconnect the L1 coupling nut from the drain for the VSV actuator.
(g) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the VSV actuator. Fluid in this container will come from the VSV actuator.
(h) Disconnect the L4 coupling nut from the drain for the modulated turbine cooling valve actuator.
(i) Install a CONTAINER 10 L(2 1/2 USGAL) at the drain for the modulated turbine cooling valve actuator. Fluid in this container will come from the modulated turbine cooling valve actuator.
(j) Install a CONTAINER 10 L(2 1/2 USGAL) at the engine LH side drain on the core drain mast. Fluid in this container will come from the VBV actuator.
(k) Install the engine kit segment shroud 5 (Ref. AMM TASK 72-24-01-400-801).
(l) Install CAP - PROTECTION and COVER - PROTECTION on all the open tubes and ports that are not used during the leak check.
(m) Close the thrust reverser doors (Ref. AMM TASK 78-36-00-410-806).
(n) Do an engine run at idle as per (Ref. AMM TASK 71-00-00-790-805) for fuel or hydraulic or oil leakage limits.
(o) Open the thrust reverser doors (Ref. AMM TASK 78-36-00-010-806).
(7) When the cause of the leak has been identified, do the steps that follow:
(a) Remove the CAP - PROTECTION and COVER - PROTECTION from the tubes and ports immediately before you connect the applicable components.
(b) Remove all the CONTAINER 10 L(2 1/2 USGAL) from the engine.
(c) Connect the L5 coupling nut to the drain for the HPTACC valve.
(d) TORQUE the L5 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(e) Connect the L6 coupling nut to the drain for the LPTACC valve.
(f) TORQUE the L6 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(g) Connect the L1 coupling nut to the drain for the VSV actuator.
(h) TORQUE the L1 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

.
(i) Connect the L4 coupling nut to the drain for the modulated turbine cooling valve actuator.
(j) TORQUE the L4 coupling nut to between 3.48 and 2.96 m.daN (25.66 and 21.83 lbf.ft )

5. Close-up
Subtask 71-00-00-410-190-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
(3) Remove the access platform(s).

Subtask 71-00-00-440-106-A

B. Do the reactivation of the thrust reverser system after nacelle maintenance (ICU) (Ref. AMM TASK 78-30-00-440-807).

Subtask 71-00-00-410-191-A

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 12:57:42 UTC