How to Replace the Inverter Coolant Pump

I just did my wife's inverter coolant pump at 127,000 miles without any issues. I was going to have the dealer do it, but that means scheduling an appointment, leaving it for a day, trusting them not to mess anything else up while they're in there, etc...easier to do it myself on my own schedule. It took under two hours including fiddling with the bleeder and a drive around the block. It's a tight space to work in but not the worst I have experienced. My hands only hurt a little.

Fingers crossed that I really got all the air out. Wife has instructions to pull over and shut it down if she sees the triangle of death, just in case.

 

That was my experience and reasoning when I did it. Plus, I bought the pump online at a better price.

Bleeding is really a non-issue for the inverter loop - put a piece of tubing on the bleeder, put the other end in the top of the inverter coolant tank, hit ready and let it bleed until there are no more bubbles.

 

Thanks! I already applied for reimbursement. After they asked me for a letter, on my mechanic's letterhead saying why the pump needed to be replaced, I called them and chided them for not even reading what I sent them.

Many weeks later, they FINALLY reimbursed me the cost of the pump.

 

Yup, that's exactly what I did. Most of the time I spent on that task was looking at the loop and convincing myself that it really, truly was that simple.

To tell you the truth, I didn't realize I could do that! My local dealer really is shady enough that I would rather spend $130 of my own money than leave a car with them for a day. Thanks for mentioning it.
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If you're having a hard time with the hoses, you have two options that don't involve lubricant:

1) Use a hot air gun to heat the hoses (a hair drier will do in a pinch). They'll be much more pliable once heated. Don't worry about damage -- these are cooling hoses, they're designed to handle higher temperatures!

2) Replace the rubber hose with one made of silicone (example: Durion® Silicone Coolant Hose - Hose - Products | Gates Corporation) The silicone hose will last longer than the rest of the car, and will stay quite pliable at any temperature. Yes, it's overkill, but think of it this way... if you want to keep your Prius on the road for 20+ years, you'll have to replace that hose eventually!

 

I got the P0A93 code, as mentioned here. The inverter water pump is in the mail so I am planning on change it myself. I saw a video here where they do not seem to replace the coolant. Is that mandatory since it is sort of difficult for me to get access underneath to the transaxle coolant drain plug?

 

Thanks for the update, Patrick. Luscious Garage has reported pump failures on late model Gen II cars, so perhaps the pump hasn't really been substantially redesigned. I'm waiting until close to the end of the recall window before taking our car in... although the pump was replaced early on.

 

But anyway I need to take the air out ... can I do it without accessing the drain plug?

I relocated to Europe with my Pri, so it's not covered by warranty.

 

Great! Thank you! At first quick read I missed the bleed nipple detail.

Btw, I forgot to say that in late 2009 I had my Pri in service for a pump replacement under a TSB. I thought it is the inverter coolant pump it was replaced ... but maybe I remember wrong, maybe it was the "coolant heat system" - CHS noisy pump ... I will check if the base of my inverter pump is black or silver.

 

I read somewhere (Luscious Garage blog) that the original base used to be black, while for the redesigned pump, the base is silver.

 

I got a new pump from an American site. I also bought 1 quart of SLLC from local Toyota for about $15 (!). So today I managed to do the pump replacement following the video made by Luscious garage and instructions from this thread. It took me about 2 hours. Then I put a tube from the bleed nipple to the coolant reservoir, left the car in IG ON (twice the start button) and topped the coolant (used only about third of the quart). While in IG ON, the coolant is flowing by the tube from the nipple to the reservoir. What I am concerned about is the fact that the pump seems to me quite noisy ... some sort of electrical noise when I put my ear at the hood level. So am not sure whether I am done with the bleeding or not.

 

Do you have any idea if the procedure is basically the same for the gen 3 ?

 

I know this is a very old thread but I had to add that this is a much easier job than the directions lead you to believe.

1) Remove driver side headlight (very easy) plus you have a ton of room.....a ton. Very easy access this way.
2) remove the 3 bolts from the old pump (leave the hoses connect a this time)
3) Do not drain the fluid. If you do it right you will only loose a quater cup of fluid or less.
4) stick a plastic bag or use something else to plug the side hole on the new pump. There are 2 holes on the pump, one on the side and one on the top. Plug the one on the side and leave enough of what you use sticking out so that you can remove it when its time to connect the hose.
5) remove the hose from the top of the old pump (it tends to be hard to remove but if you twist the hose first to break the initial crud build-up then the hose will slide off easy.
6) immediately after removing the hose off of the old pump, connect it to the side of the new pump.
7) repeat steps for hole on top pump (remember to remove the plastic bag you use to plug the hose)
8) bolt down new pump.
9) re-install headlight.
10) you are done.

This took me all of 20 minutes with my office dress clothes on.

 

It seems that the inverter coolant pump varies in times it needs to be replaced.
Was wondering what the mileage on some of the PC members Prius cars were when they had to replace inverter coolant pump because of failure , the first time,the second time, etc.
The first owner replaced the one on my car at 98 k under warrenty,now car has 152 k. I often drive a 9 hour loop on weekend tripS , every month, would hate to get stuck in the middle of nowhere. The car has no problems and no check engine lights on. You might say this is a what if scenario .... Thinking of replacing pump as preventative maintenance with 54k on current pump......
Any thoughts.