1999 Volvo Penta "WT" Models Workshop Manual, Page 280Get this manual
Lubrication System _ Description and Operation
The oil pump consists of two gears and pressure relief valve enclosed in two-piece housing, and is driven by the distributor driveshaft which in turn is driven by helix gear on the camshaftThe pump is flange mounted to the cylinder block with two bolts
The pump cover is equipped with pressure regulator valve that
regulates oil pressure at approximately 40-60 PSI {275,8-413,7 kPa) at 2000 RPMThe pump intake is of the fixed screen typeA mesh screen filters out small particles of dirt and sludge which
may be present
A baffle incorporated in the intake screen has been designed to eliminate pressure loss due to sudden surging stopsIn