TM 5-2420-230-24-2
General Engine Test Procedures - (Chassis Dynamometer) (14-05)
Section 14 - Engine Testing - Group 14
Page 14-24
B Series Shop Manual
Measure the blowby by installing blowby checking tool in
the crankcase breather vent. Connect the blowby tool to
a water manometer.
NOTE: Excessive blowby indicates a turbocharger malfunc-
tion or an engine internal components malfunction, allowing
combustion gases to enter the crankcase.
Minimum Gauge Capacity: 1270 mm H20 [50 in. H20]
NOTE: If a sudden increase in blowby occurs, or if blowby
exceeds the maximum allowable limit during any run-in step,
return to the previous step and continue the run-in. If blowby
does not reach an acceptable level, discontinue the run-in
and determine the cause.
NOTE: Avoid long idle periods. Operate the engine at low
idle only long enough (3 to 5 minutes) to check for correct
oil pressure and any fuel, oil, water, or air leaks.
Caution: Do not allow the engine speed to exceed 1,000
RPM before run-in. The internal components can be
damaged.
L-454
