[DIY] ICE & Inverter Coolant Replacement

Thanks for this. A very thorough how to. The one thing I find daunting is techstream. If you don't mind, a couple of comments:

1 For the first startup to get into maintenance mode: should that be WITHOUT foot on brake pedal?

2 Considering the infrequency of this maintenance, I'd say use the the Toyota fluids, and unless they're not readily available, replace the washers.

 

Did Toyota change remove the air release valve from the 2012 Prius? It does not have any screw to loosen. Since I don't have ICE coolant bleeder on mine, is their another method for the 2012s? I've attached the picture of what it looks like on the 2012.

 

On my 2010 it looks like that, except there's a white plastic cap, knurled, with a slot across the top.

You have the wipers and cowl off for that pic?

 

I believe the 2012 Prius doesn't have a bleeder valve. But it shouldn't affect how you would do the service, which would be the same without using the bleeder valve.

 

Would one instead have to disconnect a nearby hose temporarily to let trapped air escape?

 

Yes, I removed it to make sure I wasn't missing anything lol

 

Nutzaboutbolts has started a thread for 3rd gen coolant changes. As usual, with start to finish videos!

 

No, I think the bleeder valve has a valve to bleed air out from there, if you disconnected the hose and bleed air out from there, it would defeat the purpose and will probably cause more mess than needed. The engine warms up quicker than my Honda Accord when I do my coolant drain and refill. So just run the engine and wait till the radiator fan kicks on, the air should be bleed by then.

As for the bleeder valve, my 2012 Prius doesn't have that white cap either, they must have updated the vehicle on certain parts. There is no twisting motion either so it's basically a plastic sealed tube.

 

I continue to be puzzled by the bleed bolt deletion. I've yet to do Prius coolant change, but with Hondas the drill was to leave the bleed bolt open as you fill, until coolant start coming out, then shut it. While it's open, and if you're pouring coolant in fast, you can feel a strong gust of air coming out of the bleed bolt, that's got to be helpful. Our 2010 at least has the bleed bolt.

Also, seems strange that there's not radiator cap.

Anyway, your videos show how to do it, and it gets done.

 

The cap must be the highest point in the system.

 

The bleeder is missing on my 2011. I just popped the wire off of the temperature sensor, unscrewed it, and BURRRP!

 

I thought the bleeder valve delete was in 2012, strange. Yeah I think if you were to pull off a topmost hose at the EGR, it would accomplish the same thing: fill till coolant starts coming out, then quickly push the hose back on. Be easier with an assistant doing the pouring.

 

If you start and stop the engine several times going from cold to hot and back to cold again, then the trapped air will be carried out by the coolant. Your overflow tank level will go down as a result. The air is entrained by and dissolves into the coolant.

 

Homebrewing 101: One way to remove "entrained" air in water is to boil it.

 

Very good guide on bleeding coolant! I have done changing coolant for my inverter quite some time ago. However, I am not very happy with the temperature. The inverter seems to be running a tad bit warm. I am looking to see of I missed something during the inverter coolant replacement. So seems like I missed on doing the bleeder valve part. The tutorial I followed in youtube does not mention about this bleeder valve. And I cannot find much information on it. Lots of mention on Gen2 but not on Gen3. So can I know more information on how this bleeder valve works? Without tinkering with the bleeder valve, what are the consequences?

 

How do you know your inverter is running hot?

If you have run the car for a period of time after the drain and refill and the level is stable, job done.

If there is a dash light, there is a code present or if you've had issues with your Prius cutting out at speed, that could be the inverter water pump.

But it doesn't sound that way, so let us know how you got the too hot data.

 

Bleeder valve was on the engine coolant circuit.

 

I uses Hybrid Assistant app. It will show a lot of sensor readings and one of them are the temps. The below screenshot I taken from google but the example is shown in the red rectangle. Yellow usually means warning temp, not severe yet. In my case, my inverter temp is always around 55c (130f). Inverter temp should be less than 50c (122f) to be in "green".