Venting master cylinder reservoir diaphragm

摘要

A reservoir diaphragm for a vehicle brake master cylinder fluid reservoir has a passage in communication with the atmosphere defined between the reservoir cover and diaphragm. The diaphragm has a slot receiving a projection from the cover to normally form a seal. The seal prevents pasage of air between the reservoir and the passageway when the reservoir substantially equals the atmospheric pressure. The diaphragm is movable with respect to the projection to open the seal when the pressure in the reservoir is less than the atmosphere thereby allowing air from the atmosphere to enter the reservoir.