Section XI. OIL COOLER GROUP
ble oil cooler group in the order of index
The oil cooler group is mounted to
the engine block. It consists of the oil
cooler assembly, a water bonnet, and as-
a. If tube bundle is corroded, scale
sociated tubing and connections. The oil
deposits can be removed by either of the
cooler assembly contains a tube bundle, two
bypass valves, and a housing. On cold
engine starts, the cool viscous oil does not
flow immediately through the oil cooler and
oil filter. The cool oil fore es bypass valves,
Care must be taken to avoid dam-
located on the oil filter and oil cooler, to
aging sides of tubes.
open and the oil flows unrestricted through
the engine and to the turbocharger. As the
1. Clean tubes with a suitable 5/32
temperature of the oil increases, the vis-
inch diameter rod long enough to penetrate
cosity and pressure of the oil decreases
length of tubes.
and the oil filter bypass valves close. Now,
only filtered oil is delivered to all of the
engine parts. As oil temperature continues
to increase, the oil cooler bypass valves
Wear protective clothing and use
close, allowing the oil to flow through the
extreme caution when mixing acid
oil cooler prior to entering the oil filters.
solution, and when cleaning oil
If an oil filter becomes clogged, that oil
cooler. Always add acid to water
filter bypass valve opens and allows the oil
when mixing; never add water to
to flow directly from the oil cooler into the
acid. Avoid any contact of solution
engine. Water from the engine cooling sys-
with skin. Keep away from eyes.
tem flows through the tube bundle section
of the oil cooler to reduce the heat of the
2. Clean tubes with a solution of 15
engine lubricating oil.
percent hydrochloric acid and 85 percent
water. The oil cooler should be immersed
8 - 7 8 . REMOVAL.
in or flushed with the solution until the scale
is softened. Wash cooler thoroughly with
a. Refer to Operator and Organizational
water to remove scale and solution. Repeat
Maintenance Manual and remove oil filter
procedure as necessary to achieve proper
and washers, securing oil filler tube and
Cleaning Solvents are flammable and
gasket to cylinder block.
moderately toxic to skin, eyes and
respiratory tract. Eye and skin
protection required. Good general
cooler group in the order of index numbers
ventilation is normally adequate.
b. Clean metal components with an ap-
8-79. DISASSEMBLY .
proved cleaning solvent, and dry thorough-