STRAINER

665133 STRAINER is basically your first line of defense against all the crud that tries to sneak into your hydraulic system. Think of it as the bouncer for your pumps and valves, catching the bigger bits of metal, rubber, or whatever else breaks loose before it can do serious damage. It's not a fine filter, mind you, but it stops the chunks that would otherwise jam up a pilot valve or score a pump housing. Keeps the main flow clean enough for the finer filters downstream to do their job properly.

When this STRAINER starts getting plugged up, usually what happens is you'll see a noticeable drop in flow or pressure downstream. On a rig, that might translate to sluggish movement in a cylinder, or maybe the drill feed just isn't as responsive as it should be. Sometimes, if it's really bad, you'll hear the pump cavitating or working harder than usual because it's starving for fluid. It's a classic bottleneck situation, and it's often overlooked because it's not always a catastrophic failure, just a slow degradation of performance.

Changing this out isn't a huge job, but it's one of those things that gets pushed off until there's a problem. When you do replace it, always give the housing a good clean, make sure there's no debris stuck in there from the old one. And don't forget to check the O-ring or gasket – a lot of guys just slap the new STRAINER in and forget that seal, leading to air ingress or leaks which defeats the whole purpose.