Feuling cylinder head breathers for Harley Davidson Milwaukee-8 engines are machined from billet 6061 aluminum with square surfaces, promoting excellent umbrella valve sealing, longer main breather exit nipples with dual O-rings to promote better breather system sealing
The Factory plastic OEM breathers can be problematic, the material easily distorts especially after seeing excessive heat then the internal umbrella valve struggles to seal causing oil carry over. Another issue found with the OEM breathers is cracked and or broken exit nipples which can be caused by heat distortion and or improper fit and poor installation.
