Subaru LEGACY 2002 - Oil Pump and Relief Valve

Lubrication
OIL PUMP AND RELIEF VALVE
LU-5
3. Oil Pump and Relief Valve
! The oil pump is a thin, large-diameter trochoid roller pump directly driven by the crankshaft. Its
outer rotor and inner rotor are assembled with each other inside the rotor housing which is formed
in the rear chain cover. The rotor housing is closed by the oil pump cover. The outer rotor, inner
rotor and the oil pump cover are made of sintered metal.
! When the pump discharge pressure exceeds a certain level, the relief valve located at the outlet
port of the oil pump opens and allows excess oil to return to the inlet of the pump. The relief valve
is a single-spool type and housed in an aluminum die-cast case. It is mounted on the rear chain
cover with a metal gasket.
(1) Inner rotor (5) Plug
(2) Outer rotor (6) Gasket
(3) Oil pump cover (7) Relief valve spring
(4) Relief valve case (8) Relief valve
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B2H3889A