Hydraulic Breather Cap

A hydraulic breather cap is fitted to hydraulic reservoirs to allow air to enter and exit as fluid levels change during operation. This pressure equalisation helps protect seals and supports stable reservoir behaviour during heating, cooling, and hydraulic actuation.

Breathers typically incorporate filtration to reduce the risk of dust and moisture entering the system. If a breather becomes blocked or damaged, pressure build-up can contribute to leaks, reduced oil cleanliness, and accelerated component wear.

Breather condition is commonly checked during servicing, particularly where hydraulic oil temperature sensor readings are monitored and where cold starts make a hydraulic oil heater relevant for system protection.