5-43. CYLINDER BLOCK-MAINTENANCE INSTRUCTIONS (Continued).
PRESSURE TEST (Cont.)
(1) Attach sealing plates and gaskets as in method "a". Before attaching the last
sealing plate, fill the water jacket with a mixture of water and one gallon of
antifreeze. The antifreeze will penetrate small cracks and its color will aid in
detecting their presence.
(2) Install the remaining sealing plate and tighten it securely.
(3) Apply 40 psi (275.8 kPa) air pressure to the water jacket and maintain this pressure
for at least two hours to give the water and anti- freeze mixture ampe time to work
its way through any cracks which may exist.
(4) At the end of the test period, examine the cylinder bores, air box, oil passages,
crank- case and exterior of the block for presence of the water and antifreeze
mixture which will indicate the presence of cracks. A cracked cylinder block must
be replaced by a new block.
(5) After the test is completed, remove the plates, drain the water jacket and blow out
all of the passages in the block with compressed air.
a. After cleaning and pressure testing, inspect the cylinder block.
b. Since most of the engine cooling is accomplished by heat transfer through the
cylinder liners to the water jacket, a good liner-to-block contact must exist when the
engine is operating. Whenever the cylinder liners are removed from an engine,
the block bores must be inspected.