A hard disk drive (HDD) includes a base plate where the base plate includes a disk housing, at least one disk located within a disk shroud in the base plate, a drive cover configured to cover the at least one said disk within said base plate and a reservoir between the base plate and the drive cover and the reservoir is proximate along a periphery of the at least one disk. The HDD also includes a reservoir seal configured to isolate unstable air pressure in the reservoir from the at least one disk.