vane-type pump, PC Suction and pressure effect via reduction or enlargement of the chambers. Centrifugal force causes apex seal to fit against housing. function of the pressure relief valve. function of the V-ribbed belt drive. description ordernumber 1151 see also: Common-rail high pressure pump with fuel-delivery regulation valve Mercedes-Benz A Class diesel engine with common rail technique Mercedes-Benz cylinder head M 270 with camtronic cylinder and cylinder head with tappet control