Evening star., 1922-02-19
ny ALBERT n. ATKINSON.

The most serious defect that could
occur with the lubricating system Is
failure Of the pump. but. fortunately.
this rarely occurs. The pumps are
small affairs, but sufficiently rugged as
their work is light. Certainly they never
fan for lack of fabrication, because they
run in bath Of oil.
There are two kinds Of pumps used in
engine oihng-the gear and the plunser
types. The gear pump has two gears
revolving, one Of them being driven by
a shaft which runs down from the cam
shaft The gear teeth catch the Oil ana
carry i. around until they mesh with
each other, when the oil is squeezed out.
The pl;,nger type. is worked o'rec'iS
from the cam shaft. 1t has two check
valves. As the plunger moves towafa
the cam shaft the oil Is sucked Into the
body of the pump. one OF the cnech
valves opening to admit it, This valve
closes when the planSer stops. me
plunger is now forced in by the cam ON
the cam shaft and the OIL goes ouS ns
the other check valve. In case piece
Of dirt gets by the strainer and passes
into the gear pump the shaft Will break.
The plunger pump is more rugged put
1t depends upon spring for the return
Of the plunger. II dirt enters 1t is apt
TO jam the plunser.
Failure Indicated.
Failure of the pump is Indicated
Immediately on the dash at the pres
sure gauge or sight feed. But TINS
must not be confused with another
trouble, an air-bound pump. Where
the pump is set above the oil level
there is always danger Of its becom-
ing filed with air. 1t then fails to
pump oil, making a dangerous condi-
ton for the engine. 1t is customary
in such cases to unserew the OIL pipe .,
at the sight gauge and to inject oil
from the squirt can. This runs down
and flls the pump. "priming" 1t, as
we say. The pipe is then replaced.
the engine started and the gauge
watched. If now the pump does not
must be taken apart for inspection.
Another serious trouble Is clogged
oil pipe, which does not often happen.
AS the oil must pass through q
strainer before it can enter the pump.
A stuck piston or a burned-out bear
is no way of detecting it until the
damage is done, but fortunately it is
rare.
A recent development in lubricating
to the difficulty of evaporating the
heavy gasoline now in use. This
works down from the combustion
space If the cylinders or rings are at
all worn. if the mixture is too rich or
the engine cold. 1t condenses in the
oil base and thins the OIL. increasing
the friction and so cutting down the
power Occasionally some of the oil
should be drawn off on the hand or
on a piece of paper and inspected for
thinness. or course, it will be seen
to grow blacker with increased mile
age. but should not be any thinner.
As soon as you are satisfied that the
gasoline is mixing with it you should
change it Immediately. 1t is OF small
value CO.. pared with the gasoline
which must be burned to overcome
the increased friction.
OIL Grows Dirty.
AS time goes on and the car piles
up it's hundreds of miles the oil grows
dirtier and thicker, unless there is
gasoline condensation Dust gets in
from the outside, carbon comes down
from the cylinders. the lighter parts
of the oil evaporate and in time the
bottom of the oil base becomes
clogged with heavy muck. This
has been known to obstruct the flow
Of oil to the pump, stopping the cir,
culation entirely. Thf usual (and
posit is to drain OF the engine under
its own power This loosens the
muck so that some of it may then
lie drawn out when the oil base is
drained. but it also splashes the fine
grit into the bearings. where it acts
as fine grinding compound.
The only way to remove this muck
and grit is to drop the oil base and
take it out by hand. This Is
troublesome process, but it is far bet.
ter than stirring up the. grit and
splashing it into the bearings.