A precooler for an aircraft engine system includes a precooler core and a precooler inlet to direct a compressor bleed flow into the precooler core to cool the compressor bleed flow. The precooler further includes a precooler outlet to direct the compressor bleed flow from the precooler to a selected component of the aircraft engine system and a precooler bleed port through which a portion of the compressor bleed flow is diverted to a secondary component of the aircraft engine system. The precooler bleed port is oriented such that flow entering the precooler bleed port must substantially reverse direction from a direction of the compressor bleed flow through the precooler.