Powersteering fluid change interval, and others
 

Let me start by saying I know there are a lot of threads on this already; I've read most of them, and also read on the owner's manual, service schedule, and service manual of my car.

I will be doing a transmission/differential oil change this weekend at 40k miles (got the car at 37k, no idea if it was done before). I did oil change a couple weeks back. I've been reading about other maintenance stuff I could also do. Been reading about changing brake fluid (still unsure, need to read more), and about steering fluid and engine coolant.

Now to my question: Everybody seems to have a different opinion on how often you should be changing the power steering fluid, but nobody seems to back that up. I can't find anywhere in either the owner's manual, service schedule, or service manual of my 2014 370z that says anything about powersteering fluid. Service manual says which fluid to use, and how to do it, but nothing about how often. So, where are you all getting those intervals from?

Plus question: Service Schedule says Engine Coolant should be changed at 105k miles first, and then every 75k miles. Why is people changing it every 20k-30k here? Where are you getting that from?

Thanks in advance for the help!

Any input, anyone?

I doubt you will find a lot of info on the subject since most people just check the level. PS is kind of a bastard child that doesn't get much attention.

All the PS pumps I've run into are a PITA to change the fluid on, so most people never do it. Some will siphon off what they can from the reservoir and refill.

I like to change all the lubricants (including PS fluid) after a good break-in period - 15k-30k miles - to get rid of break-in trash. After that, I tend to change a little more frequently than the manual calls for.

What does the manual call for PS changes? i couldn't find anything about it.

I don't remember (I haven't owned a Z in a few years). It may be considered "lifetime" or "dealer-serviced only" as with the auto transmission.

I'm a bit obsessive about maintaining fresh lubricants in any car I own but not as much for what is basically hydraulic fluid (it provides some lube but mainly transfers power). On cars I have owned over the last 40 years or so, I've never done more than siphon-and-replace (multiple times if fluid looks dirty) and had no problems. If the PS system was a lot easier to drain and/or I had had more PS problems, I might worry about it more. YMMV

i usually do the turkey baster removal trick, gets most of it, do it again after a few hundred miles...generally around 25K i start replacing fluids.
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