Hydraulic filler breather filters are commonly used to maintain the health of a reservoir and protect the surrounding environment, they are a vitally important component in your hydraulic system as they allow air in and out of the reservoir as the water levels change.How do filler breathers work?The filter breathers clean the air that enter the reservoir as fluid levels reduce from their normal system cycling. Without a breather filter, contaminants such as water and dirt, water can deplete fluid additives and form rust, whilst dirt can change oil chemistry so its important this filtration takes place to the hydraulic reservoir.When the hydraulic fluid levels changes within a reservoir, air is drawn up through the filter element, trapping dirt particles. The air is then passed through the desiccant bed and traps moisture before entering back into the reservoir. The filler breathers can become ineffective if not monitored and or changed periodically.