The crankshaft of most pumps turns on two
bearings, one on either side of the pump. They are held in place with a
plates or housings.
One housing is blank and the other has a hole in it
for the crankshaft to extend as a shaft for the motor or engine.
On the blank side there is only one place
for the oil to leak, That's the o-ring that seals the bearing housing to
the crankcase housing.
On the crankshaft side there are two places for
oil to leak, one in housing seal to the crankcase. The other is the oil seal that the
crankshaft runs through.
If the pump has never been taken apart
before then it's not likely that the housing o-rings on either side of the
pump are leaking. There is no wear on these o-rings.
culprit is the oil seal on the crankshaft. This is where the wear takes
place. It's quite easy to replace this seal but it does have to be done
from the inside of the crankcase so the crankshaft has to be pulled out of the
There are 3 other places for oil to leak from the crankcase. Check
the drain plug on the bottom of the pump and make sure it is tight. Check the
oring on the plug.
pumps have an oil sight gauge window. These usually screw into the side
of the pump. Check that it is tight. There may be an o-ring so
check that too.
fill cap on top of the pump has a small hole in it to allow crankcase air
to expand and contract as the pump heats and cools. If there is too
much oil in the pump the oil will splash out the oil filler cap. Most
pumps need to be filled halfway with oil.
which is usually the filler cap as well, will show the right level
for the oil.
a typical pump cut-a-way view check this out.
Make sure you replace
the pump oil with your pump manufacturers recommended
non-detergent 30 weight oil
SOME OF THESE OPERATIONS CAN BE
EXTREMELY DANGEROUS. IF YOU DO NOT HAVE SUFFICIENT TRAINING IN THESE PROCEDURES, WE RECOMMEND YOU
SEEK ASSISTANCE FROM A