Optimal Prius Maintenance

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How many miles on it currently, and how long have you had it? Following or either not in the schedule, in the schedule but often overlooked, or in schedule somewhere else in the world:

1. In the US schedule, but a little "subtle": do an in-depth brake inspection/clean/lube tri-yearly or 30K miles*.

2. Not in the schedule (US or CDN): change transaxle fluid. A first change at 12 months or 10K miles, then 5 years or 50K miles. Perhaps none thereafter. Or every 10 years or 100K miles.

3. Not in the US schedule, but in the Canadian schedule: change brake fluid every 3 years or 30K miles.


* Whichever comes first.

 

Good question on the brake fluid change. Normally this is done with a special electronic tool that opens up the different passages in the brake controller so you can flush it out properly.

At that mileage I would change every fluid unless you're sure it's been done. Radiator, Brake, Transmission (engine oil too of course). Just change and monitor.

Also, have the spark plugs been changed?

I would recommend 5,000 mile or 6 month (whichever comes first!) oil changes with a good oil such as Toyota brand or Mobile One and a Toyota filter from the dealer. Don't use a different oil grade, don't use high mileage oil unless you're leaking oil and are going to replace the seals soon and don't use any other special oils like high zinc or diesel oil or such. Just use what the manual says paying attention to both the weight and the API or ILSAC rating should be.

 

change it now, and then do some reading. there are various opinions here, since toyota calls it lifetime. some say every 30k, some every 50, etc. you'll have to make your own call.

 

Yeah most important transaxle fluid change is the first. I'd suspect manufacturing detrous, gears meshing and so on, happens right off the bat, then subsides. Don't have Prius c Repair Manual, but info in transaxle fluid change link in my signature (for 3rd gen) is mostly relevant.

 

for the brake maintenance, see if @NutzAboutBolts has a youtube video, idk.
you're mostly looking them over, and lubing the slide pins

 

It’s probably the best guide available, but keep in mind that the automakers, for all the engineering and failure rate data that they have, are hardly making their recommendations as disinterested parties:

• If the vehicles last too long, they get fewer chances to sell new ones.
• Vehicles with greater maintenance requirements are less attractive, especially for fleet customers.
• Dealers object to longer service intervals, since they have fewer chances to sell profitable add-ons.

If this car is practical transportation, rather than a collector’s item, this might not be the right objective. The car won’t last forever, no matter what you do: it’s subject, as it has been since it was made, to corrosion and other wearing processes that won’t be suppressed by any cost-effective preventive or restorative maintenance.

I’d suggest, instead, trying to do just enough to keep the car reliable as long as you’re likely to own it. If you can find a trustworthy mechanic or develop the skills to do it yourself, use a condition-based maintenance strategy: do the inspections mentioned in Toyota’s Repair Manual (more info) and Warranty & Maintenance Guide, and perhaps others, and let the results determine what, if anything, to do beyond the scheduled items.

It’s no use to sink money and time into maintenance that might well be of no benefit, if you end up disposing of the car relatively soon because it’s not economical to replace a brake booster with master cylinder assembly, HV battery, catalytic converter, or some other expensive part—assuming you can still get one when needed.

Do you have evidence that this is cost-effective, in terms of reducing the likelihood of transaxle failure during the car’s practical remaining service life?

As far as I know, nobody’s done a randomized controlled trial of transaxle fluid changes or any of the other folk wisdom here, and all we have are anecdotes of the form, “I did ___ and didn’t notice any trouble, so you should do ___, too,” which overlook the possibility that the trouble might not have happened without the treatment.

 

The good news is the Prius c is a different engine than the regular Prii of that era. Transaxle fluid on this car does not fill up metal and other gunk like conventional transmissions but it does have electric motors in there, so using the factory fluid is essential. That said, transaxle failure on any Prius is rare.

Besides the oil changes on a 5k mile basis, do not drive the car even one extra mile if it overheats. All aluminum engines react badly.

The hybrid battery overheating is also a deal breaker. It is air cooled from the cabin; run the ac in hot weather and keep the inlet duct clean. Know where it is so you can ensure it does not get blocked with bags etc. Nevertheless, a ten year old hybrid battery is very likely to need replacement in your ownership. Go with new cells when the time comes.

 

No. This is however, the first car we've ever had that didn't call for a transmission fluid change.

My (admittedly selfish) take is that it's very easy and inexpensive to do, and not risky (with a little common sense). I'd rather err on the side of overkill. The prudent approach, in hindsight: do at least one transaxle fluid change, early in the car's life.

 

“High mileage” descriptor with oil means it has additives for the purpose of swelling gaskets and seals. It’s best avoided, employed only when oil consumption is getting out of hand and leaky seals are suspected. Once you start with it it’s best to stick with it: if your seals were drying/shrinking, the cause of oil loss, the high mileage oil will swell them, reduce oil loss, but going back to reg oil (either synth or not), the gaskets and seals will shrink, likely worse than at the outset.

 

Use normal synthetic not the special high mileage synthetic. You don't want the seal conditioners or higher viscosity of high mileage oils in an engine with variable valve timing and tight clearances.

 

Why? Just want info to make informed choices, not trying to contradict anyone.

 

If the gas is "top tier" it means the major oil company has used plenty of quality additives. No more fuel injector additives needed. Top tier are the big names like Chevron, Mobil, Exxon, Shell including Costco. In reality all gas has detergent additives and these cars don't have a fuel injector issue.

They have an oil ring issue but only 3-5k oil changes is likely to help. The engine cleaners are more likely to damage rather than help. There is no magic additive in a can. Pure marketing hype to lighten your wallet.

 

See attached link...

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More is not needed on these engines and won't work on direct injection engines where the gas bypasses the valves. Not to say the gen3 engines don't get severely carboned up, they do. But additives won't help. Octane won't help. Some believe oil catch cans can reduced the liquid accumulation in the intake manifold. Does not stop carbon buildup.

The good news: Your Prius c is a different engine than the regular Prius. Less problems.