I am approaching 90,000 miles on my 2011 Prius, and want to check in as to what truly needs to be done at this maintenance interval. They quoted me $638, and talked of the usual oil change/rotation, and then speak of changing the inverter coolant, engine coolant, throttle body fluid (I believe). Are all of these necessary to do at this time in order to keep my Prius in good shape? If it makes any difference I actually leave this car for rather extended periods, but so far so good, it's running fine after doing that for intervals for the past five years. Just checkin in to see whether I just let them go for it at the dealership, or question what they are doing further. Thanks!
Engine coolant change is 100k miles (or 10 years), and inverter coolant 150k miles (or 15 years). Both are 50k miles (or 5 years) thereafter. I believe 90k (or 9 years) IS an in-depth brake inspection, NOT just a visual inspection. Which they never mentioned I assume. Maybe they said throttle body cleaning? There’s no fluid there. You can do TB cleaning yourself, watch @NutzAboutBolts video, linked in pinned thread at top of 3rd gen maintenance forum. Torque for the 2 hold-down nuts/bolts is 7 ft/lb IIRC. I can verify, post repair manual excerpt if you’re interested. It’s best to remove TB for a more thorough cleaning, and NO need to pull off the coolant hoses; they have plenty of slack.
Throttle body and intake manifold torque values in attached. Also, link has info and more repair manual excerpts, regarding aforementioned EGR/Intake cleaning and Transaxle fluid changes: Bad Flywheel | PriusChat