Perkins L4 Workshop Manual - L-36 Fleet
Perkins L4 Workshop Manual - L-36 Fleet
Perkins L4 Workshop Manual - L-36 Fleet
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lA MARINE ENGINES-W.4<br />
exchanger) cooling also incorporate a water pump<br />
of the centrifugal variety.<br />
Ceotrüugal Type Water Pump.<br />
Since the centrifugal type water pump employed<br />
on those Marine engines incorporating indirect<br />
(heat exchanger) cooling systems is identica!<br />
with that pump titted to <strong>L4</strong> engines in genera!.<br />
maintenance instructions for this type of pump<br />
may be obtained by referring to Section Q.<br />
Rubber Impeller Type.<br />
This type of pump is gear driven inasmuch as a<br />
gear wheel attached to the impeller driving shaft<br />
is in constant mesh with the engine camshaft gear<br />
whee!. the pump itse!f being !ocated on the starboard<br />
side of the engine directly below the<br />
dynamo.<br />
Removal aod Dismaotling.<br />
First dis~onnect water inlet and outlet hoge<br />
connections. The pump may then be detached by<br />
removing the setscrews that secure it to the engine<br />
timing case.<br />
To dismantie the pump, proceed as follows :-<br />
Remove rear end cover.<br />
Remove impeller.<br />
Remove wearplate.<br />
W ith the front bearing cover removed. a suitable<br />
press may be used to press out the impeller shaft<br />
together with the front bearing, leaving the driving<br />
gear wheelloose in its housing.<br />
The cam in the impeller housing maf then he<br />
detached by removing the single securing setscrew.<br />
Remove rubber seal in impeller housing.<br />
Remove rubber .. 0 ,. ring.<br />
Remove distance-pieces.<br />
The driving gear wheel housing and impeller<br />
shaft rear hearing may then be removed from the<br />
pump body.<br />
Finally remove front rubber seal.<br />
To reassemble the water pump, the reverse<br />
order of the above procedure should be adopted,<br />
care being taken 'when replacing the rubber<br />
impeller that the blades alllay in the same direction<br />
relative tv the rotation of the pump. i.e.<br />
blades trailing.<br />
When reassembling, ensure that the rubber<br />
impeller is coated with a layer of water resisting<br />
grease. It should also be noted that, if necessary,<br />
the impeller may be dismantled without removing<br />
the water pump.<br />
When replacing the cam fitted in the impeller<br />
housing. be certain to treat the entire top surface.<br />
rear face and securing setscrew hole with a suitable<br />
jointing compound. NOTE : This cam will go<br />
into place one war only.<br />
With the assem bied pump fitted to the engine.<br />
backlash between the pump and I:amshaft gears<br />
should be .003 in. to .009 in. (.08 to .23 mm). To<br />
achieve this in production. two joints may have<br />
been fitted between the pump gear wheel housing<br />
and the ~ngine timing case. Should this be SQ.<br />
ensure that both joints (or two new joints) are<br />
replaced when refitting the pump.<br />
ti the engine is to be withdrawn from service<br />
for any length of time it will be necessary to<br />
effect lubrication of the rubber impeller at the<br />
commencement of the storage period. Tbis may<br />
be achieved by removing the end cover (Item 1.<br />
Fig. W.2) and placing glycerine between the vanes<br />
if the impeller (Item 2. Fig. W.2).<br />
Exhaust Manifold.<br />
The exhaust manifold is water cooled and<br />
constructed of cast iron. An air release cock is<br />
provided at the forward end of the manifold<br />
jacket. whereby any air present in th~ water<br />
cooling system may be removed.<br />
OU Cooler.<br />
Provision is made at the front end of tl.e sump<br />
for the fitment of an engine lubricating oir cooler.<br />
With this, heat from the engine oir is lost as it<br />
circulates round a system of tubes through which<br />
are pumped water from the cooling system.<br />
With the fitting of a hydraulic gearbox, a<br />
further similar type oir c;ooler must be titted in<br />
order to cool the gearbox oir. tThe mounting for<br />
this additional cooler is on the top of the gearbox.<br />
The pump necessary to lift the oil is ~nclosed in<br />
the gearbox-<br />
Sump Oir Pump (Hand Operated).<br />
On the majority of marine installations it is<br />
impossible to gain access to the sump drain plug<br />
which is situated on the bottom of the sump.<br />
Therefore, in order to facilitate the draining ot<br />
the engine oil. a hand pump may be provided<br />
This pump when used must be titted ~'emote from<br />
the engine. Drainage of the sump is etfected by<br />
operation of the pump af ter attachir:g a leng th of<br />
suitable piping to the inlet side of the pump and<br />
placing the free end of the pipe into the SIImp via<br />
the dipstick orifice.<br />
~<br />
".