油箱在第一次加滿后，經開機運轉應該向油箱內進行二次加油，并使液壓油到油位觀察窗的上限，以確保油箱內有足夠的油液循環(huán)。在使用過程中由于液壓油氧化變質，各種理化性質下降。因此，應及時更換液壓油，其換油周期可按以下幾種方法確定。

1、綜合分析測定法。依靠化驗儀器定期取樣，測定主要理化性能指標，連續(xù)監(jiān)控油的變質情況。
Laboratory equipment regularly rely on sampling, measurement of key physical and chemical properties, continuous monitoring of the situation of oil deterioration.
2、固定周期換油法。是指按液壓系統(tǒng)累計運轉小時數換油，通常按使用說明書要求的周期進行更換。
By hydraulic systems operating hours accumulated oil change, usually required by manual replacement cycle.
3、經驗判斷法。通過采集油樣與新油相比進行外觀檢查，觀看油液有無顏色水分沉淀泡沫異味黏度等差異，綜合各類情況作出外觀判斷和處理。
By collecting oil samples compared with new oil visual inspection, whether the color of the water to watch the oil viscosity and other differences in precipitation foam odor, appearance comprehensive judgment and making all kinds of cases handled.