When is it time to replace the filter in a hydraulic system?

Lately, I've noticed that the loader's hydraulic system has been feeling a bit sluggish, especially after several hours of continuous use. At first, I thought it was the oil, but after changing it, the situation hardly improved. Then I checked the filter and realized it had been replaced quite a while ago, although no one had written down the exact date. Now I’m wondering whether I should wait for obvious problems to arise or if it’s better to replace it proactively. What signs do you look for to know it’s time to change the filter?

I used to base my choice almost entirely on the filter’s appearance, but that’s not the most reliable approach. In some cases, it looks fine on the outside, even though a significant amount of debris has already built up inside. When I was looking for a replacement for my equipment, I came across Hengst filtration products, and I started paying closer attention to maintenance intervals and operating conditions. If the equipment is operating under heavy load or in a dusty environment, I wouldn’t extend the replacement interval unnecessarily. I also monitor pressure changes and how the hydraulics behave during operation. If the system starts to run slower or exhibits unusual fluctuations, it’s time to check the filter. But I wouldn’t replace it based on just one symptom—I’d rule out other causes first. Since we switched to a regular maintenance schedule, we’ve had noticeably fewer surprises like that.

I started keeping track of maintenance dates right on my phone because I’m terrible at remembering these kinds of things. Before, I always had to try to remember when the filters and oil were last changed. Now, after a service, I just add a quick note with the date and operating hours. It’s much less stressful that way, especially when the equipment is used almost every day.