Chrysler V-8 Marine Engines manual., Page 24Get this manual
very 100 ntilotion valve and cap assembly from tlic rocker coverIf the valve is not lugged, hissing noise will be heard as air passes through the valve and mng vacuum should be felt when fiiifii?r is placed over the valve eplace the ventilator valve and cap assembly and remove the inlet breather capWith the engine running at idleloosely hold piece of stiff paper over the oil fill pipeIt should be sucked against the oil fill pipe with holding final test should be made to be certain the valve shuttle is freeA clickin oiw should be heard when the valvr is siiaken (engine not running)I oise is heard, the unit is satisfactory and no further service is necessaryIf tit valve docs not click when shaken or if the paper is not sucked against the fill pipe, the valve shoutd be riplat-ed.Do not attempt to clean the valve stalled, it will be necessa