Toyota Prius Water Pump Change (Inverter coolant pump)

My Problem...

I had a Toyota Prius (2008 model) since early 2011...

No even a small repair (or even a bulb change) upto 2013 July (for 2 1/2 years)...

On one sunny afternoon, after driven about 15km with five on-board, several warning lights including big red triangle with warning sign appeared. Multifunction display also showed a Japanese warning like this;

I drive few hundred meters more and parked safely and shut down the car. then I restarted it, but same unusual warning lights and upper quarter of the display with a warning continued...

As the car can be driven without any noticeable problem, I drove it for a short distance more but then noticed Air Condition system also not working (No cool, only the blower)...

I stopped the car, called the local Toyota dealer...

Luckily, I could contacted a very good person who listened me patiently and told me that 95% it could be the 'water pump failure'. I was about 10km away from that dealer and he further told to Switch off the AC and OK to drive the vehicle to them, for the water pump replacement....

I was shocked to know that the repair will cost around Rs. 50,000/- (LKR) (pump 34,000/-, labor 12,000/-, and rest for the coolant). At that time I couldn't afford that much and decided to do it later...

So without any other problem except AC and the warning signs, I drove it another 20km and came to the destination...

Googling...

I called a known local garage person but he was not comfortable with Hybrids and reluctant to do any repair of electric side of the car. So I google to find a local place, but I came across the following links:

http://priuschat.com/threads/inverter-coolant-pump-takes-a-dive.36513/page-4#ixzz2YytkAmN4



I found many other pages and videos about this, but above two was the most helpful...

After seen those I decided to Do It Myself and did it in my own way and it worked very well for me at less than a half of the estimated dealer cost...

Definitive diagnosis...

This must be the very first step to begin. I let the coolant and inverter to cool down for abut 2 hours, opened bonnet. While cooling I inspected and identified the inverter, inverter coolant reservoir and the water pump.

The water pump is situated just behind the left head light, under/near the fuse box there. It receives two hoses (top one from the coolant tank, other one from the under side of the Inverter) and a electric wires connector)

1. Turn the car on to IG mode (press the power button, without stepping on the brake - orange light on the power button).
2. open up the coolant reservoir cap, look for turbulence of fluid inside. If none, the pump isn't working.

I also check the wire connector and two hoses for any errors.

Where to buy the pump?

I contacted the local Toyota agent again and confirmed that pump is about Rs 34,000/-. Then I contacted few other auto shops and managed to get a genuine one from a known shop for Rs 19,000/-.

Part number was G9020-47031

I also bought a good Ratchet wrench with 10 mm, 12 mm sockets. and 10" extension. (about  Rs 1,000/-)

How I replaced the pump:

1. Removed left side head light as shown on the video above.
2. Removed two pump screws.
3. Removed the electric wire connector from the pump.
4. Clamped two hoses attached to the pump *(see below)
5. Removed two hoses from the pump.
6. Attached two hoses to the new pump and removed the clamps.
7. Attached the electric wire to the pump.
8. Screwed the pump bracket.
9. Turn the car on to IG mode  for about 20 min to remove any air bubbles.
10. If coolant reservoir level is below the MIN mark, you need to replace the coolant.
11. Replaced the head light and other all others back.

Then I drove the car for a very short distace... WOW, all the warnings went off and the AC is back..!!!

Tools Used:

*Hose clamps: Made myself with four pvc pips (~4") and four nuts and bolts (~4")