I was dead wrong about hydraulic fluid additives - here is what changed my mind after 12 years

For over a decade I swore by plain mineral oil in my Otis elevators. I thought additives were a waste of money just selling snake oil to green mechanics. Then a building in downtown Cleveland had a valve failure that left two cars stuck for 6 hours back in March. After swapping to a detergent-based hydraulic fluid from a local supplier, I have not had a single sticking valve in 8 months. The old fluid had sludge buildup that I could actually see when we drained the tank. Anyone else made the switch and noticed a difference in older systems?

3 comments

3 Comments

ninas671mo ago

One thing I don't see mentioned is how additives affect the seals in older systems. We had a 1979 Otis in a medical building near Akron that started leaking from every piston seal after switching to a detergent fluid. The stuff cleaned out the sludge so well it ate the swollen old seals right up. Took us three months and a lot of frustration to get it stable again. Just something to watch if your equipment is really old.

hannah_perry1mo ago

That sounds about right. The irony of "cleaning" a system so well it destroys itself is peak old elevator maintenance. Bet the building manager loved that three month headache. Guess the lesson is if it's held together by decades of sludge and swollen seals, you're better off leaving the chemical warfare out of it. You try saving one thing and end up creating a whole new mess. Ever run into a situation where the fix made things way worse than the original problem?

drewgonzalez1mo ago

ninas67 you just reminded me of a time we flushed a 1980s Otis in Columbus and ended up with a geyser of fluid in the machine room because a seal gave out mid-cycle. Real mess.