300SD (126.120) L5-3.0L DSL Turbo (617.951) (1982)
Oil Pressure Regulator Valve: Description and Operation
66
Closing plug
67
Compression spring
68
Pin
69
Piston
a
Washer
Pressure relief valve in oil pump
The damped oil pressure relief valve (7 bar gage pressure) is integrated in oil pump.
A damping device (washer "a") has been installed to make sure that the pulsating oil pressure generated by the oil pump is not transferred to piston (69)
of pressure relief valve with subsequent deactivating noise.
Starting at an oil pressure of 7 bar gage pressure the piston (69) is displaced against the pressure of compression spring (67) and clears the deactivation
cross section.
Simultaneously some of the oil (arrow) flows into the area behind washer (a) by way of two control cross sections in washer (a). The oil flowing through
the control cross sections opposes the piston movements initiated by the pulsating oil pressure and will thereby dampen the piston.