STRAINER, OIL

550 673 91A STRAINER, OIL is essentially your pump's first line of defense against all the crud floating around in the tank. Think of it as a coarse filter, catching the bigger bits – metal shavings, bits of seal, general gunk – before they even get a chance to enter the pump's suction side. If this thing wasn't there, or if it was bypassed, you'd be looking at a much shorter lifespan for your main hydraulic pump, or even your charge pump, depending on where it's plumbed in.

When this strainer starts getting plugged up, or if it's damaged and letting too much through, you'll usually notice your pump starting to cavitate. That's that distinct growling or whining sound, especially under load, as it struggles to pull enough fluid. You might also see your hydraulic functions get sluggish, or even erratic pressure readings, because the pump just isn't getting a steady, unrestricted supply. It's like trying to drink a milkshake through a tiny, bent straw.

Honestly, these strainers are often overlooked. When you're troubleshooting pump issues, always pull this thing out and give it a good look. Sometimes a quick clean will sort it, but if the mesh is torn or really gunked up beyond reasonable cleaning, just swap it out. It's cheap insurance compared to a new pump. And don't forget to check the O-ring on the housing when you put it back together; a tiny leak there can cause cavitation just as easily as a plugged screen.