Chain Lubrication - Stihl MS 440 Service Manual

4.3

Chain Lubrication

Warning!
In the event of trouble with the chain
lubrication system, check and
rectify other sources of faults before
disassembling the oil pump.
Condition
Chain receives no oil
Machine losing chain oil
Oil pump delivers insufficient oil
MS 440, MS 440 C
Cause
Oil tank empty
O-ring on oil line to crankcase
defective or oil line damaged
Oil inlet hole in guide bar is
blocked
Intake hose or pickup body
(strainer) clogged or intake hose
ruptured
Valve in oil tank blocked
Teeth on pump piston and/or worm
worn
O-ring on oil line to crankcase
defective or oil line damaged
Piston bore in pump housing worn
Adjusting screw and/or control
edge on pump piston worn
Piston bore in pump housing worn
Remedy
Fill up with oil
Remove oil pump, fit a new O-ring
and refit or replace the oil pump
Clean oil inlet hole
Clean intake hose and pickup body
(strainer) with standard solvent-
based degreasant not containing
chlorinated or halogenated
hydrocarbons / replace intake hose
and pickup body
Clean or replace valve
Install new oil pump and/or new
worm
Remove oil pump, fit a new O-ring
and refit or replace the oil pump
Install new oil pump
Fit new adjusting screw and/or oil
pump
Install new oil pump
9