When to Replace Engine and Inverter Coolant?

Not to derail this issue- but what do you do with spent coolant nowadays?
Back in the day- we used to just let it run down the driveway and we washed it into the grass with the garden hose. Somehow I can't see doing that with the stuff they use in today's vehicles..

 

Read the label.

 

I replaced mine at 35k miles after reading recommendations on here to change early. I will probably do it again at 70k since it was so easy to do with an Air Lift device.

 

contact your local trash hauler. most have a "Hazo" House where they collect hazardous waste. here, we can take it in for free as long as we are county residents. there is a limit but its not really an issue. the limit was imposed to prevent businesses from taking their waste (mostly paint, etc) there for nothing.

 

annnnd so it begins. "if you want to keep your car a long time, changing (insert fluid here) is necessary to extend the life of your vehicle". So you're asking for opinions from this group that can be based only on "feeling" and not a demonstrated benefit...I mean there's no research or data from this group that could ever confirm any kind of benefit from early fluid swaps. People on this forum still line up to swap fluids early.
You will now get an assortment of opinions probably ranging from 30kmi to 80kmi because obviously the manuf. recommended interval for ANYTHING is too long by about 100%.
So the question you need to ask is "Is there a documented incidence of (insert fluid here) related failures in my make/model of car?" (are problems with this fluid(like your dexcool example) appearing on a regular basis on this group).
If the answer is "no" (it is) then there's no reason to even suspect that the manufacturer's interval is too long(as you seem to have already determined). Recreational coolant change will likely be this summer's sensation.

 

I may never replace it. But if i do it will be around 150k

 

Coolant and components are matched to a high degree in modern cars -- years ago you had all kinds of metals in the cooling system... and very little plastic - and the engines leaked into the coolant. Modern coolant does not degrade like it did 25 years ago. The dealers do not do flushes when you have a "coolant service" they just dump the radiator and refill -- so the fluid in the engine stays. I have been surprised at how clean the coolant is at 5 years on those that call for 5 year changes -- our Lexus at 8+ had changed color but had very few noticeable suspended particles. I just did a change on a 2002 MB with 100k -- as recommended and it was surprisingly clear. Make sure you use the correct fluid -- we do not mix coolants -- we purchase the correct fluids from the manufacture's dealer. If you have a concern do a simple change using one gallon of the correct Toyota fluid at 5 years - you will clear any particles that have settled at the bottom and refresh the coolant -- the proper coolant is under $30.00.

 

yes indeedy, I still believe the day of the sealed system is years not decades away. Honestly, the MB oil change was so unsatisfying...you suck the oil out through the dipstick tube, drop a new filter in the top, refill with oil. no tools(aside from a pump), no gloves, you don't even get under the car....every 15kmi

 

Cost for Toyota SLL ranges between $20-$30/gal depending on your relationship with your Toyota dealer.

I had a dealer do an engine coolant drain and refill at 31k for $59.95. They were only able to remove 1 gal upon draining from the radiator. The flat rate tech was on a huge hurry so it is possible that more would have been removed if time was not a concern.

I will do the inverter coolant soon, and will use Techstream to cycle the pump for bleeding.

Coolant is inexpensive compared to cooling system issues. I may even experiment and add BG super cool to the engine loop to refresh the coolant that was not removed.

 

The tech at the dealer did not use an airlift to refill, and I do not plan to use one for the inverter either. I had originally planned to do the engine coolant myself, but other things got in the way. IIRC the shop manual has a procedure for bleeding the inverter which involves a bleed screw and cycling the inverter pump to remove the air pockets.

 

Hobbit's done a pretty comprehensive look at SLL inverter coolant: 100K maint - 5

He also documented an engine coolant change: 100K maint - 5

Inverter coolant serves as a lubricant for the pump, a likely factor in pump longevity.

 

I would not put any additives into any system as a preventive measure -- doing an early refresh will accomplish what you want and will not run the risk of any air lock problems and the corresponding overheat concerns ..... I'm a firm believer in the "if it's not broken" system.

Hobbit's info is interesting -- if you read any of the articles in the fleet maintenance regarding coolant they are about the same ........ the stuff really will last as long as many cars are on the road - or require a part that will result in a refresh

 

On a 2008 prius, my inverter fluid is at the low mark. Should I just add fluid to the fill mark?

I don't want to drain it myself, so if necessary, that must mean the dealer and big bucks?

 

Yes. You can buy the correct Toyota Coolant at dealership, likely premixed with water, but verify. You're pretty much locked in to buying a gallon.

With the car cooled down, remove the reservoir caps and top up to the full line.

 

Den49, at least in the pdf of US maintenance guide I have, it's 120K miles or 12 years for both engine and inverter coolant. Forget where I even got it though.