Coolant flush

@NutzAboutBolts does show the radiator petcock in the video.

I don't think a "flush" is warranted, unless there's some contaminant in there. What would you use for a flush, water? This has ramifications, if you finish off by just refilling with pre-mixed Toyota coolant, it's going to be a bit diluted by the residual water. Also, what are you doing with the flush water? Running it down the street to the nearest storm drain?

One thing not mentioned in the video is the engine block drain bolt, around the back of the engine. I suspect you'd want to remove the cowl first, for better access. NutzAboutBolts has video on that too, lol: the spark plug video. Apparently not much fluid comes out, may not be worth it.

Someone else here disconnected a coolant hose at the exhaust (exhaust heat is used to speed coolant warm up), and drained a fair bit of coolant there.

 

In for the answer, diagrams, directions.

Disregarding the pre-mix coolant ratio, on other cars multiple drain and refills can be done without removing thermostat.

Get car to operating temp. Open drain plug on radiator, drain into containers, close plug. Refill with distilled water. Watch for air bubbles that may be introduced. Bring to op temp again (this opens the thermo). Then redrain. Repeat until water runs clear. Then drain and refill with proper coolant and ratio. I do not know if there are special considerations for a Prius, hence in for the answer!

 

AFAIK you can only buy the Toyota spec'd coolant pre-mixed. So once you flush with straight water, and fill, you will end up with slightly over-diluted.

Here's info on the thermostat:

 

I swapped the fluid in my Prius at 85,000 and the fluid that came out was very clear. I even ran about a quart through a coffee filter, but the only gunk it caught were a few floaties that fell into my drain basin from being underneath my car.

This isn't the old days where radiator fluid turns brown and gets full of metal.

 

How many miles on the car? Those sealers can be nasty?


Sorry -- just saw the miles.

Good luck

 

I don't suppose you thought of replacing the head gasket? Oh well... you poured in the sealer gunk, so let's see if it works. It's a lot less work, that's for sure.

I wonder how many of us Gen III Prius owners will still own our cars when the engine rebuild days come. It's really funny how I bought my 2010 and then 2012, and the discussions were totally different than the Gen II discussions. And these days... what Gen IV owner cares about transaxle and brake fluid replacement? They're writing about dash rattles and why the DRL's come on at the same time as the parking lights. It's kinda funny.