Vent: I think the common wisdom on hydraulic fluid is way off

I was reading through some old manuals last week at the shop in Tulsa and found out the standard 12-month flush schedule we all follow might be overkill. The manufacturer spec on a lot of these 737 actuators actually says the fluid can go 18 months if you test for particle count first. Nobody ever talks about that. I've been doing this for 8 years and I always just followed what the senior guys said, but now I'm starting to wonder how much extra money we've spent on unnecessary flushes. My lead just laughed when I brought it up, said we do it because that's how it's always been. Has anyone else actually looked at the OEM data on this stuff?

3 comments

3 Comments

wesley_jones1mo ago

Yeah robin591 my buddy's shop got dinged hard by the FAA for not following OEM specs instead of the old schedule.

nathan9011mo ago

Honestly, that "that's how it's always been" thing is everywhere, not just in shops. I see it with homeowners too, like people changing their HVAC filters every month when the filter box clearly says 90 days. They just do it because their dad did it or some guy at the hardware store told them once. It's like people would rather follow a habit they heard from someone else than spend ten minutes reading the actual instructions.

robin5911mo ago

That thing about "that's how it's always been" gets me. My old man used to say the same thing about changing motor oil every 3,000 miles, turned out he was just repeating what his dad told him in the 70s. I'd bet your lead has never actually read those manuals either.