How To: Change Inverter Coolant

You *did* bleed the little valve back into the reservoir, right?
Otherwise you'll have air trapped in the transaxle.
.
_H*

 

Nice idea to use that funnel that screws onto the coolant container. I had been using a regular funnel, but yours should be more convenient.

 

One of the most overlooked maintenance items on your car is the coolant system. Most people don't even think about it until they are on the side of the road with the hood up and steam pouring out of the radiator. This traffic nightmare can be avoided by some simple routine maintenance.

 

Thanks for the video.btw. there are 4qts to a gal. you probably looked at the liter conversion.

 

Thanks for making this video and posting it! I watched it and it helped me get the job done. I especially liked the way you captured the sound of air in the pump before bleeding.
I attached a 2' length hose to the bleeder screw and fed the coolant from the hose back into the reservoir.

 

Would it be about the same procedure to change the inverter/converter coolant for a 2002 Prius?

 

It is "about" the same in concept. The reality is that it is more difficult to get air out of the system. The Classic inverter coolant system has two bleed valves.

 

I've been meaning to ask: what is the reason for this? Do they both have to be bled during the process? Do they go to different loops?

 

Great video. I'll be looking it up when I get near 100k. Doesn't hurt to keep myself informed.

 

I don't know why the Classic inverter loop is harder to bleed or why two bleed valves are involved; I just know that it is much harder based upon personal experience. Plan to spend two or three hours working on it, the first time you do this.

I suggest that you 1) listen to the inverter coolant pump before you begin work, so that you can hear what it sounds like, 2) look at the fluid turbulence in the inverter coolant reservoir so you know what that looks like, and 3) measure the volume of the drained coolant, so that you know how much needs to be added.

You need to work with both bleed valves, and cannot declare victory until you no longer hear air bubbles in the inverter coolant loop, you see turbulence in the inverter coolant reservoir which proves that fluid circulation exists, and you've added substantially the amount of fluid that was previously drained.

After you've worked on the bleeding process for a while and don't seem to be making further progress, it might help to take the car for a short drive "around the block". The increased inverter heating from the drive seems to encourage some of the trapped air to purge out. However you don't want to drive long distances until proper coolant flow has been restored.

 

Awesome video, made my coolant change a piece of cake. Thanks!

 

I did the inverter change, but I have been bleeding it for about 20 mins, but i cant seem to get it to go back to the normal sound. Its still making the weird whining noise. Any tips?

 

Do you have 2G or Classic?

What is your bleeding process?

 

2G,
I am just opening the bleeding screw, and I attached a little rubber hose to the screw, and had it go back into the reservoir. Is there anything else i need to do?

 

OK, that is the normal procedure. In fact you are doing better than me, as I don't bother to run a hose from the bleed screw into the reservoir. I just open the screw, watch fluid with bubbles come out, and close it when it looks like the fluid doesn't contain bubbles.

The inverter normally makes a high-pitched whining sound around 5 kHz when the car is READY.

The inverter coolant pump should sound like an aquarium pump when the car is IG-ON or READY. You should not hear air bubbling in the line, and you should see fluid turbulence in the reservoir. If you observe the turbulence and do not hear air bubbles then you can declare victory over this project.

 

I fixed it! I ended up attaching a rubber hose to the bleeder valve, and had it flow to a container that was ground level and kept pouring in coolant to the reservoir. Im going to assume that once the flow got going, and the momentum was able to get the air out.