Removal of the Servo Fuel Heater [CFMI]

TASK 73-11-20-000-001-A
Removal of the Servo Fuel Heater

CAUTION: USE TWO WRENCHES TO REMOVE OR INSTALL THE TUBE COUPLING NUTS:

ONE WRENCH TO HOLD THE UNION, AND
ONE TO LOOSEN OR TIGHTEN THE COUPLING NUT.

THIS PREVENTS DAMAGE TO THE PARTS.

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

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	COVER - PROTECTION
No specific	AR	PLUG - BLANKING
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

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

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-A	Opening of the Fan Cowl Doors
TASK 73-11-20-600-001-A	Preservation of the Servo Fuel Heater.
Servo Fuel Heater

3. Job Set-up
Subtask 73-11-20-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 73-11-20-010-050-A ** ON A/C NOT FOR ALL

B. Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR

4. Procedure
Subtask 73-11-20-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Servo Fuel Heater
(1) Disconnect the fuel pump HP tube (250) from the FUEL IN tube (260).
(2) Disconnect the FUEL IN tube (260) from:
(a) The FUEL IN nipple (10) of servo fuel heater (80).
(b) The fuel pump, and remove FUEL IN tube (260).
(3) Remove the OIL IN tube (240) as follows:
(a) Remove the 4 bolts (150) which attach the OIL IN tube (240) to the OIL IN port of servo fuel heater (80). Remove and keep the gasket (155).
(b) Cut and remove the lockwire which safeties the coupling nut (210).
(c) Loosen coupling nut (210) to disconnect OIL IN tube (240) from the tube (215) which goes to the lubrication unit.
(d) Remove OIL IN tube (240).
(4) Disconnect the FUEL OUT hose (140) from the FUEL IN nipple (10) of the servo fuel heater (80).

NOTE: It is not necessary to disconnect the FUEL OUT hose (140) from the HMU to permit the removal of the servo fuel heater (80).

(5) Remove the OIL OUT tube (130) as follows:
(a) Remove the 4 bolts (110) which attach the OIL OUT tube (130) to the OIL OUT port of the servo fuel heater (80). Remove and keep the gasket (120).
(b) Cut and remove the lockwire which safeties the coupling nut (135) of the hose interface (100) with the tube (130).
(c) Loosen coupling nut (135) to disconnect the OIL OUT tube (130) from the hose (100) which goes to the oil tank.
(d) Remove the OIL OUT tube (130).
(6) Detach the fire detection loop from bracket (40).
Then, remove the six nuts (30) and washers (20) which attach the servo fuel heater (80) and the bracket (40) to the studs of the main oil/fuel heat exchanger (60).
(7) Carefully back off the servo-fuel heater (80), move it upward and remove. Keep the gasket (70).
(8) If necessary, remove the two nipples (10) from the servo fuel heater (80). Discard O-rings (90) and (95).
(9) Install PLUG - BLANKING or COVER - PROTECTION on all the open ports and orifices.
(10) Preserve the servo fuel heater (Ref. AMM TASK 73-11-20-600-001).

[Rev.10 from 2021] 2026.04.01 02:55:23 UTC