(3) The oil cooler element should be
removed and cleaned periodically, or at the time of
each engine or marine gear overhaul, to prevent
overheating of the marine gear oil.
b. Removing Oil Cooler Element (fig. 4-59).
(1) Drain the cooling system.
(2) Remove engine oil filter and bracket.
(3) Remove oil tubes from engine oil cooler
(4) Matchmark the end of the oil cooler
cover, cooler element, and cooler housing with a
punch or file so they can be installed in their same
(5) Remove the bolts and lockwashers
securing the oil cooler cover to the oil cooler housing.
Then, pull the cover away from the element.
If necessary, loosen the oil tube clips at the
side of the cylinder block.
(6) Remove the oil cooler element from the
Figure 4-60. Transmission oil cooler details.
oil cooler housing (fig. 4-60).
(7) Remove the gaskets from the oil cooler
(2) Clean the element before sludge hardens. If
over, element, land housing.
the oil passages -are badly clogged, circulate an Oakite or
c. Cleaning Oil Cooler Element.
alkaline solution through the core and flush thoroughly with
(1) Clean oil side of element. Circulate a
clean, hot water.
solution of trichloroethylene through the core passages
with a force pump to remove the carbon and sludge.
(3) Clean water side of element. After cleaning
the oil side of the element, immerse it in the following
solution: Add one-half (1/2) pound of oxalic acid to each two
This operation should be done in the open
and one-half (2 1/2) gallons of solution composed of one-
or in a well ventilated room when
third (1/3) muriatic acid and two-thirds (2/3) water. The
trichloroethylene or other toxic chemicals
cleaning action is evidenced by bubbling and foaming. The
process must be care fully watched and, when bubbling
are used for cleansing.
stops (this usually takes from 30 to 60 seconds), the
element should be removed from the cleaning solution and
thoroughly flushed with clean, hot water. After cleaning, dip
the element in light oil.
Cleaning an oil cooler element is not recommen ded
where the history of usage shows a marine gear
failure which has released metal particles from
worn and broken parts, into the lubricating oil. In this
instance, the replacement of the oil cooler is strongly
d. Installing Oil Cooler Element.
(1') Affix a new gasket to the oil cooler housing (fig.
Figure 4-59. Transmission oil cooler removal.
(2) Affix a new gasket to the inner face of the oil
(3) Install the oil cooler element into the oil cooler
housing with the matchmarks previously placed on the
element and housing in alignment.