TM-9-2815-220-24

AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL FOR AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines

TM-9-2815-220-24 - Page 225 of 1563

TM 9-2815-220-24

CYLINDER COMPRESSION TEST

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TEST (Continued)

NOTE

High cylinder pressures can be caused by combustion of lubricating

oil in the cylinder combustion chamber.

If this occurs, allow

combustion gases to escape prior to taking compression readings by

cranking the engine with the starter for 30 seconds with the fuel

supply shut off.

4. After all 12 cylinders are checked, determine the pressure difference between high and low

cylinder readings.

a. This variation should not exceed 70 psi. (483 kPa).

b. If compression readings are below the low limit of 330 psi (2,275 kPa), the engine

motoring rpm should be checked to be sure that it is 140 to 180 rpm.

c. Compression should be checked again to confirm the previous readings before submitting

an engine for overhaul.

AFTER TEST

1. Remove gauge assembly (3) from compression adapter (2).

3

2

WP 0033 00-3