KKM

My 2012, with about 80,000 miles on it has the original coolant, so probably time for a flush. Have not really driven it much since the pandemic and working from home. Also driving mostly our PHEV since its basically getting free fuel from our solar panels, awesome combo. Is it just a flush and fill or should I flush some distilled water through it before refilling with new coolant? Should I also flush the inverter coolant while I'm at it? I read it might be a little more work to ensure no air bubbles are incorporated. Will do a search for DIY video unless someone can recommend a good tutorial. Also just use Toyota long life coolant or Amsoil or Pentofrost as some has recommended?

morganc

Both coolant jobs are easy. Most YT videos will show you how to purge the inverter coolant circuit without tripping codes (it's bascially just putting the car into "on" but not "run" for no more than "3?" seconds, so as to not cause a code, then top up the reservoir. Repeat this until you don't hear anymore bubbles. I would certainly recommend flushing both with distilled first. I did about 4 gal flush in my engine system and 2 gal flush in the inverter side. No issues. Just use the Toyota LL, it's not much more money than generic and you do it so infrequently.

Another good "while you're in there" is just replacing the engine loop water pump, since they're prone to failure.

KKM

Morgan, thanks for your reply, I was thinking of replacing the water pump, even though it's such low miles, both coolants still looks nice and pink but 12 years has past and it might be deceptive and acidic, don't have any paper to test the pH so will probably replace the pump although I read that just replacing the innards and not the whole pump should be sufficient. I'll have to do a little more research.

Clutchless

See this video from The Car Care Nut as he is a Toyota Master Tech. He has many other great videos. He shows how to put it into maintenance mode to do this service.

There is no need to flush, as he explains. Just drain and fill and bleed the system. Also the invertor coolant lasts a lot longer than the engine coolant, but if you want to change it, go ahead!

morganc

Absolutely, if you can just get the rotor for pump (from a reputable manufacturer) and a new pump-to-block gasket, then you're off to the races. The plastic over the rotor cracks and jams it up. Pump is otherwise normally fine. The rotor, on its own, doesn't come as an OEM part (I believe) so you're automatically into aftermarket.