TM-9-2320-272-24-2

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 2 OF 4

JUNE 1998

TM-9-2320-272-24-2 - Page 802 of 991

TM 9-2320-272-24-2

4-12. CYLINDER HEAD REPLACEMENT

THIS TASK COVERS:

a. Removal

b. Installation

INITIAL SETUP:

APPLICABLE MODELS

M939/A1

SPECIAL TOOLS

Head holding fixture (Appendix E, Item 7)

Cleaning brush (Appendix E, Item 28)

TOOLS

General mechanic’s tool kit (Appendix E, Item 1)

Torque wrench (Appendix E, Item 145)

MATERIALS/PARTS

Cylinder head gasket (Appendix D, Item 94)

REFERENCES (TM)

TM 9-2320-272-24P

EQUIPMENT CONDITION

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Water manifold removed (para. 4-27).

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Exhaust manifold removed (para. 4-25).

• Fuel crossover connectors and valve crossheads

removed (para. 4-30).

• Injectors removed (para. 4-32).

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Engine fuel supply and return tubes removed

(para. 3-17).

GENERAL SAFETY INSTRUCTIONS

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Compressed air source will not exceed 30 psi

(207 kPa).

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Eyeshields must be worn when cleaning with

compressed air.

NOTE

All three cylinder heads are replaced the same way. Only one is

covered in this paragraph.

1. Following “outside-in” loosening sequence, remove twelve screws (2) and washers (3) from cylinder

head (4).

NOTE

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Assistant will help with step 2.

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Tag cylinder head for installation.

2.

Remove cylinder head (4) from cylinder block (1) by lifting straight up.

3.

Remove cylinder head gasket (5) from cylinder block (1). Discard cylinder head gasket (5) and clean

gasket remains from mating surfaces.

4-120