Preservation of the Hydromechanical Unit (HMU) [CFMI]

TASK 73-21-10-600-001-A
Preservation of the Hydromechanical Unit (HMU)

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	CONTAINER 5 L (1.32 USGAL)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP2442)	engine oil

C. Referenced Information

REFERENCE	DESIGNATION
Hydromechanical Unit

3. Job Set-up
Subtask 73-21-10-869-051-A ** ON A/C NOT FOR ALL

A. Not Applicable

4. Procedure
Subtask 73-21-10-020-051-A ** ON A/C NOT FOR ALL

A. Preparation for removal

CAUTION: DO NOT HOLD OR MOVE THE HYDROMECHANICAL UNIT BY THE TORQUE MOTORS. CHANGES TO THE CALIBRATION OF THE HYDROMECHANICAL UNIT CAN OCCUR.

(1) Put a CONTAINER 5 L (1.32 USGAL) under the Hydromechanical Unit (HMU) to catch fuel and oil released when you do this procedure.
(2) Remove the following from the new HMU and keep the gaskets:
(a) Screws (90) and shipping cover (80).
(b) Gasket (70, 100, 130)
(c) Screws (120) and shipping cover (110).
(d) Screws (150) and shipping cover (140).
(e) Shipping plugs (10, 20, 60, 190, 210, 30, 50, 170, 200, 40, 180).
(f) Shipping caps (220, 160).
(3) Remove the nut (250) and the washer (240) from the HMU studs.
(4) Remove the nuts (260) and the washers (270). Then, remove the bolt (300) and the washer (290).

Subtask 73-21-10-550-050-A ** ON A/C NOT FOR ALL

B. Remove the new HMU from the shipping block (280). Keep the gasket (230).

Subtask 73-21-10-680-050-A ** ON A/C NOT FOR ALL

C. Fully drain the fuel from the old HMU.

Subtask 73-21-10-620-050-A ** ON A/C NOT FOR ALL

D. Put 1l (0.25 USgal) of engine oil (Material No.CP2442) into the PCR port of the old HMU.

Subtask 73-21-10-420-051-A ** ON A/C NOT FOR ALL

E. Install the shipping plug (200) in the PCR port.

Subtask 73-21-10-620-051-A ** ON A/C NOT FOR ALL

F. Carefully turn the HMU a minimum of one turn to apply engine oil (Material No.CP2442) to the internal parts.

Subtask 73-21-10-020-052-A ** ON A/C NOT FOR ALL

G. Remove the shipping plug (200) from the PCR port.

Subtask 73-21-10-680-051-A ** ON A/C NOT FOR ALL

H. Fully drain the engine oil (Material No.CP2442) from the PCR port.

Subtask 73-21-10-420-052-A ** ON A/C NOT FOR ALL

I. Preparation for installation:
(1) Install the shipping plugs, caps, covers and gaskets to the old HMU as follows:
(a) Gasket (70), shipping cover (80), and screws (90).
(b) Gasket (100), shipping cover (110), and screws (120).
(c) Gasket (130), shipping cover (140), and screws (150).
(d) Shipping plugs (10, 20, 60, 190, 210, 30, 50, 170, 200, 40, 180).
(e) Shipping caps (220, 160).
(2) Install gasket (230) on the shipping block (280). Align the holes in the gasket (230) with the holes in the shipping block (280).

Subtask 73-21-10-550-051-A ** ON A/C NOT FOR ALL

J. Install the old HMU on the gasket (230) and shipping block (280).

Subtask 73-21-10-420-053-A ** ON A/C NOT FOR ALL

K. Safety the HMU on the shipping block:
(1) Install the washers (240) and nuts (250) on the HMU studs.
(2) Install the bolts (300) and washers (290) through the HMU flange and shipping block (280).
(3) Install the washers (270) and nuts (260) on the bolts (300).

[Rev.10 from 2021] 2026.04.01 02:55:57 UTC