Filler Breathers

Clean, Dry Air for Reliable Reservoir Operation

Hydraulic filler breathers – also known as tank filler and breather filters – play a vital role in protecting hydraulic systems from contamination. Installed on the reservoir, they filter both the incoming air and the oil during tank filling, ensuring that only clean, dry air enters the system and that fluid remains free from harmful particles and moisture.

At Hydraulics Online, we supply filler breathers from a wide range of global manufacturers – including Ikron, MP FIltri and many others – with expert advice to help you select the right solution for your system.

Our website shows only a selection of what we supply. For impartial advice and access to our full range of hydraulic components, contact our expert team.

Filler Breather. For impartial advice and access to our full range of hydraulic components, contact our expert team.

Hydraulic tanks must breathe to function properly. As fluid moves in and out of the reservoir:

Air is drawn in when the pump retracts and fluid enters the cylinder
Air is expelled when fluid returns to the reservoir

Without a breather, or if the breather is blocked, this airflow is restricted – leading to:

Overpressure – which can cause leaks or damage seals
Vacuum conditions – which may result in cavitation, pump damage, and reduced flow rates

Standard Mesh Filter Breathers

Include a fine mesh to trap solid contaminants
Often paired with a differential pressure switch to indicate clogging
Require regular inspection and maintenance

Desiccant Filter Breathers

Use particulate filters and a desiccant bed to remove moisture from incoming air
Prevent water ingress, which can degrade hydraulic fluid and cause erratic operation
Must be monitored for desiccant saturation and filter clogging

By choosing the right breather type, you can significantly reduce the risk of contamination and extend the life of your hydraulic components.

Protect against solid and liquid contaminants
Prevent pressure imbalances in the reservoir
Reduce risk of cavitation and pump damage
Improve fluid cleanliness and system reliability
Support long-term system health with minimal maintenance

These benefits make filler breathers essential in mobile, industrial, marine, and energy-sector hydraulic systems.

How often should filler breathers be replaced? This depends on operating conditions, but regular inspection is key. Desiccant breathers should be replaced when the desiccant is saturated or the filter is clogged.

Can filler breathers prevent water ingress? Yes – desiccant filter breathers are specifically designed to trap moisture from the air before it enters the reservoir.

Are differential pressure switches necessary? They’re highly recommended for systems where breather clogging could lead to performance issues or safety risks.