A small valve, filter, or open port installed on gearboxes, crankcases, and hydraulic reservoirs. It prevents pressure buildup caused by thermal expansion or fluid displacement. Without a breather, internal pressure can blow out shaft seals or cause erratic fluid flow.
Heard on the job
Check the gearbox breather to make sure it isn't clogged with dirt, or we'll start pushing oil past the input seal.
Also heard as
- breather valve
- vent