Oils can and do loose their viscous properties over time. However, I’ve not heard of a “recommendation to change oil” if there has not been a problem related to the oil itself. Over the years the only time I’ve seen oil changed is when the hydraulic oil looses its lubricious properties and begins to bind the hydraulic piston to the ram seal (through a glazing process) resulting in a chattering in slow speeds or an outright stalled cab seized in the packing gland for the same reasons, OR water contamination of any sort or degree. The former of the two reasons results in callbacks in which depending on your contract cost the company money.
There might be other answers to your questions, but that’s my two cents on the question based on my 34 years in the elevator trade, but I’m no expert either.
NOTE: Replacing the oil in your 5 stop elevator has a few more twists than simply replacing the oil. Purging the 70’ jack and hydraulic lines of old oil. Draining the reservoir tank, 6 or 7 empty barrels and hazardous disposal etc all add up. But $11K? I don’t know. But you can as the owner get other estimates for the job IF you choose to move forward.

Yes, this must be some sales tatic from Otis. As we have been getting these calls a lot. Strange its the same price on west coast also. That is the same cost that they are telling the customers on East Coast. There is no code requirement for the oil replacement. I would venture to say that Otis is just throwing this out there and seeing how many customers take the bait.

They are trying to take advantage of you. We are all hurting in this economy and companies are putting alot of pressure on their sales people to sell billable work. Truly needed or not.

You don't change the oil in hydraulic elevators in this industry unless it's contaminated (water or dirt got in the tank) or it's been severely burnt (catastrophic motor burn up/welded contactors). I've been installing hydraulic elevators for 15 years and have never changed oil in one. I've taken care of and maintained hundreds of hydraulic elevators that are up to 60 plus years old with the same oil and they run fine and have no reason to change it. It's not like a combustion engine where it's being contaminated. I honestly don't think it needs to be changed. I agree with solidstate on this one..

For what its worth, I'm on the east coast and oil today is roughly 11.25 a gallon.

Thank you all for your sound advice. I appreciate it. Sounds like we are OK and only need to be concerned if there are symptoms. I was surprised by the $2500 oil disposal fee. Safety Kleen here in SOCAL will dispose of a barrel of oil for $150....How much oil would come out of of 5 stop elevator like ours?

Roughly three barrels or 150-160 gallons typically

That price is ridiculous

I don't do oil changes but I will add a couple bottles of Cat additive if the oil is old to help restore some properties that it may have lost due to age or heat.

https://peterbiltparts.com/brands/ct-1u9891

I have been working on clearing violations with an abused motel 3 stop inground hydro. Working through all the rust, deteriorated sill, and rotten wood was a real challenge.

I have only been involved with this unit for the last month. Not part of the violations but instead a new issue that maintenance and the guests have been complaining about.
Only in the down direction at start there is a loud thud/ bang. Always happens at the 3rd going down and intermittently at the 2nd going down. Even in cartop inspection.

Speaking with maxton tech support about the valve. He quickly mentioned that the piston is most likely sticking and binding up do to lack of lubrication with old or burnt oil. He suggested lubricating the piston with maxglide or other additive. Mentioned to lift the wiper and poor onto the seal. if that stopped the thud then suggested to add a gallon to the power unit.

elmcanic sounds like as you mentioned. The piston is dry. What have you done in this situation??

I have used Maxglide before in a few different situations and it works very well. If stick slip is really your issue, Maxglide fixes it. Adding it directly to the piston is much more effective than just adding it to the tank and waiting.

As mentioned, an additive such as Maxglide or the product Cat Oil (Caterpillar trade name) which works to free up the binding properties of hard or tight packing can be used. However, I’ve seen instances where two or more bottles of a additive were used but the hard breakaway remained. Time for jackhead seal replacement. “The better the effort,the better the result”. Repacking or new seals; I’m not sure if you’re a licensed elevator, lift LULA tech, but if not, you’ll need to leave this work to a licensed elevator/lift contractor. And prying the wiper back to pour a product below the wiper ring means you’ll need to be under the unit, in the pit to do this. Again, “the better the effort…” is an appropriate reminder.

elmcannic Im certainly no expert, are you? Im sure your not on a forum for just giving advice. Surely you have gained knowledge and opinion from others since 2010.
What is more disturbing to me is working for a CET/ QEI that owns a registered elevator company and has never installed or serviced ever. Better yet put unqualified persons to do the work and figure it out on their own. I have worked along side "mechanics" with 10-15 years "experience" and they don't know where to start with wiring better yet read a schematic.
no b.s. I have 5 years experience, licensed, and do pretty damn good install/service. Certainly don't pride my self with perfection but I give my best effort.

Ive done a hand full of hydro seal replacements, couple telescopic twin posts (1 beings two weeks ago), 1 casket lift jack, and assembled 4 tradesman twin post jacks.
To reseal a jack in this area runs about 8-15k.(depending who does it) But facilities like this one would leave it running rough till an inspector or monitor writes them up.
Therefor I reach out to the community for advice and knowledge to attempt a bare minimum fix to resolve the issue.
I prefer to give the better effort but they don't want to pay for best result. You definitely should understand this part being in the field as long as you have.

Well at this point I hope you’ve had some success with either of those oil additives and take care in bringing that motel hoist way back up to a more solid standard. And if the additives didn’t provide the desired results, I hope there are packing props or rail pins on the job!