Dean Portable Filters MF90 Series Installation & Operation Manual page 23

Filter Pump Fails To Pump Oil
Disconnect flexible oil return
hose. Make sure it is cool before
handling. Try blowing air through
Filter
pump
fails to
pump
oil.
If filter unit has a
heater, turn heater
ON and allow to
heat for 20
minutes.
the hose.
Can you blow
No
air through it?
Yes
Insert flexible oil
return hose into
filter pan and turn
pump motor ON.
Does oil flow through oil No
return hose?
Yes
Proceed with normal
operations.
Submerge hose in very hot water,
keeping the water out of the hose.
Water in the hose will cause severe
splattering when hot oil is circulated
through the hose.
Once shortening has had time
to soften, reconnect hose to
filter pump.
Blockage is between bottom of the filter
pan and the flexible hose quick
disconnect. Go to "Blockage Between
Filter Pan and Flex Hose Valve.
6-3