Coolant change

That's pretty much what I did, but (as noted by @ChapmanF) Repair Manual recommends to fill to "B" line on reservoir, put cap back on, and run in Maintenance Mode till radiator fans come on. Something like that, see attached.

FWIW, on Canadian purchased Toyota Super Long Life Coolant bottles I have, I see no expiration date. There is a date stamped on the bottle, but just one, and I think it's manufacture date.

 

I know it says that but if you don’t pull a vacuum first then allowing an easy path for the air to escape works faster. Plus you usually need to top off after a drain and fill with no bleeder.

 

I probably have a little too many questions here, if anyone cares to answer those

 

Changing the water pump is optional but if you do change it, do the thermostat as well. Only oem parts! Many counterfeits and aftermarket pumps will fail quickly.

The proper coolant is either one. You should change fluid much more often as they have anti-corrosive properties as well. A large amount remains in the system so all you are doing is mixing new with old. Changing twice as often is good practice and can be an easy diy job. This could save your head gasket if the coolant is changed frequently.

Similar benefits with brake fluid changes are possible for expensive master cylinder/brake booster system. Don’t forget the inverter coolant.

In my experience very hot temps are more likely to trip inverter temp alarms (car symbol with !) especially if stuck in traffic with AC operation. In this case the immediate area ambient temperature is even hotter. Be sure both coolant fans work on high using a bidirectional scanner and ensure the undercovers are attached.

 

Sometimes, reading the Toyota manual, I give myself a little extra-credit homework, namely: ok, what would have been their reason for saying to do it that way?

For me, sometimes that helps things sink in that I could have missed on first reading. For example,

• the cooling system on this engine is a degas-bottle system. The air doesn't need to escape; there's room in the degas bottle for it. When you start the fill at the B line (above full), you have put pretty much the right amount of coolant in—the engineers knew the volume of the system pretty well, including how much air it might trap, when they put the B line where they did.
• when you're done, the fluid level went from B down to full, because the trapped air traded places with it in the bottle; it didn't have to escape.
• when you have the cap on as the manual directs, the system reaches operating pressure during your warmup. That's roughly twice atmospheric (1 atmosphere, gauge), so whatever air pockets are in there are squeezed to half size, possibly making them more mobile through the system, 'til they end up in the degas bottle as the system was designed.

I've never had a chance to sit down with the engineers and say "ok, did I reconstruct your thinking right?", but I do what I can.

When I follow the procedure in the manual, it all goes pretty smoothly according to plan, and the level tends to drop from B right down to FULL when things are cooled down, and pretty much stay put thereafter.

 

I guess the expiration date of 2 years from the manufacturing date mentioned on the container just suggests the shelf life, not the actual periodic change period?

Unfortunately, I have found only this with an imminent (about 5 days from today) expiration date. The dealers here are low in supply and do not have any with a more recent date of manufacture.

 

Since coolant was never replaced in mine -

1. Should I perform radiator cleaning with a Radiator Cleaner? For example, Liqui Moly Radiator Cleaner https://www.liqui-moly.com/en/radiator-cleaner-p000197.html

2. Is there any other process for better cleaning?

3. Is radiator cleaning a good thing to do at every coolant change, say every 3 years / 30,000 kilometers?

4. Does the inverter require any sort of cleaning during coolant change?

 

No x4