TM 5-2420-230-24-2
Cylinder Head (002-004)
B3.9 and B5.9 Series Engines
Page 2-8
Section 2 - Cylinder Head - Group 02
WARNING
Wear appropriate eye and face protection when using
compressed air. Flying debris and dirt can cause bodily
injury.
Wash the cylinder head in hot, soapy water solution.
After rinsing, use compressed air to dry the cylinder head.
WARNING
Use skin and eye protection when handling caustic
solutions to avoid personal injury.
CAUTION
Do not use caustic or acidic solutions to clean the
cylinder head capscrews. Use of these solutions can
cause corrosion.
Use a petroleum-based solvent to clean the capscrews.
Clean the capscrew thoroughly with a wire brush or a soft
wire wheel, or use a nonabrasive bead blast to remove
deposits from the shank and the threads.
Inspect for Reuse (002-004-007)
Straightedge and Feeler Gauge
Cylinder Block Combustion Deck Inspect
Use a straightedge and feeler gauge to measure the overall
flatness of the cylinder block. The overall flatness, end-to-
end and side-to-side, must not exceed 0.075 mm [0.003
in].
Inspect the combustion deck for any localized dips or im-
perfections. If present, the cylinder block head deck must
be ground.
Refer to the Alternate Repair Manual, Bulletin No. 3666109,
for grinding/milling procedures and limitations.
Cylinder Head Cracks - Reuse Guidelines
The reuse guidelines for a cylinder head with a crack ex-
tending from the injector bore to the valve seat are as
follows:
If the crack does not extend into the valve seat, the cylinder
head is reusable.
L-804
