Perkins L4 Workshop Manual - L-36 Fleet

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Precautions against damage by trost should he
taken if the engine is to be left exposed to
inclement weather either by adequately draining
the water system or where this is not convenient.
an anti-freeze of reputable make and incorporating
a ~uitable corrosion inhibitor may he used.
Should it be your policy to protect engines trom
trost damage by adding anti-freeze to the cooling
system. it is advisable that the manufacturers of
the relevant mixture be contacted to ascertain
Yv'hether their products are suitable tor use in
Perkins engines and also to ensure that their
products wil! have no harmful effect on the cooling
system generally. It is OUT experience that the
best results are obtained from anti-freeze which
conforms to British Standard 3151.
Where the use of an anti-freeze is contemplated
in respect of an L4 marine engine employing a
closed circuit cooling system. advice should be
sought trom the relevant anti-freeze manufacturers
seeking assurance that their product will have no
detrimental effect on the rubber impellor of the
fresh water pump.
When draining the water circulating system it
is not enough merely to open the radiator drain
tap; the ODe on the cylinder block must also be
opened. This tap is located midway along the
fuel pump side of the cylinder block.
Wnen the engine is drained the water pump is
also drained. but rotation of the pump may he
preventm by :-
FROST
Page F 3
(a) Locking of the impelJor by ice due to thr:
pump drain hole being blocked by sedi.
ment.
(b) The locking of the seaJ through the freezing
of globuJes of moisture bet ween the sea]
and the gland.
Operators are therefore advised to take these
precautions when operating in temperatures beIoVv
freezing point :-
(1) Before starting the engine, turn the fan and
" ater pump by hand, this will indicate if
freezing bas taken place. If freezing bas
taken place, this should tree any ice formation.
(2) If it is impossible to turn the pump by hand,
the radiator and engine should be filled with
warm water.
(3) To avoid this trouble, the operator should,
when all water bas been drained. run the
engine tor a tew seconds at idling speed,
thus dispersing any moisture remaining in
the pump.
Af ter an anti-freeze solution bas been used. the
cooling system should be thoroughly flushed in
accordance with the manufacturer's instructions
before refilling with normal coolant.
If the foregoing action is taken, no harmful
effects should be experienced, but Perkins Engines
Ltd., cannot be held responsible for any Crost
damage or corrosion which may be incurred.