WEICHAI & PSI SERVICE MANUALS AVAILABLE ONLINE AT FLYPARTSGUY.COM Figure 9 Intake Air System CLOSED CRANKCASE VENTILATION Weichai engine uses a closed crankcase system as shown in Figure 10. The breather separates the crankcase oil/gas mixture and lets the oil return to the sump and sends the gas into the intake system. Figure 10 Closed Crankcase Ventilation System WEICHAI EMISSION-RELATED INSTALLATION INSTRUCTIONS GET YOUR WEICHAI & AFTERMARKET SERVICE PARTS AT FLYPARTSGUY.COM