Water pump and alternator/water pump belt replacement

The water pump and belt can be replaced by a good mechanic, doesn't have to be the dealer. You can check around for mechanics that can do the work but the price the dealer quoted you isn't all that bad. I would think a non dealer would charge around $300 for the job.

 

Is your coolant level going down, or is the engine coolant pump leaking noticeably? If not, then you can wait a bit.

Also, there is no alternator in the Prius. The belt only runs the pump.

 

Sometimes coolant level may only go down on radiator and not on overflow tank. So if you only check overflow it still might have leaked.

 

I recently had my serpentine belt changed when I went in for an oil change. Then on my next oil changed, 4 months later, the dealer told me now my engine water pump is leaking slowly. THEY WANTED $506 for it. After seeking advice on from here on changing the water pump, it is to my attention that you might want it done at the dealership, especially for that price, and find a coupon for 10% off if you can. Your ma and pa mech might not purge the air bubble out when completing the job, causing you more issues later on down the road. now, i am assuming your ma and pa would know how to purge the air bubble out when replacing your coolant. but i wouldn't take the chance because with the dealer, you can always come back to them and said u screwed up. when its only $400 bucks, i would take that deal.

 

good advice. ^

 

That's not bad advice because its very difficult to
Remove the airlock with an ice coolant change.

Make sure u say u want the coolant changed as some may not change the coolant. This is the optimum tine to do it. They use Toyota software laptop to turn on the CHRS motor which helps circulate the coolant when bleeding.

When u pick up the car for a while while heat is on and radio off listen carefully behind the dash for water rushing or gurgling sounds. This means there is still air in the system still which is bad. Seen many posts where dealer did shoddy bleed job.

If me in the am the next day I would remove the top cover to access the rad cap and check if coolant low.
Should be right to the top. Then with flashlight
Check the overflow reservoir for proper coolant.

Just cause its the dealer doesn't mean they wont mess it up.

 

I'm at 140000 miles on original water pump and belt.

Many (most?) Gen2 Prii show signs of water pump leakage by about 80000 miles as evidenced by colorful pink salts at the lower belt pulley. Many Gen2 owners replace at this juncture, in many cases replaced under extended warranty. In my case I re-filled (with the special Toyota red coolant fluid) and monitored and the leaks stopped.

 

You mean you refill it with the "Toyota super long-life anti coolant" and the leak stopped by itself? that goes against the law of nature. If it starting to leak, it would increase over time.

 

When monitoring engine coolant level, I hope you are looking at the coolant level in the radiator itself, and not just relying upon observing the level in the overflow reservoir. When the engine coolant pump bearing starts to leak, it seems that air can enter the system via the bearing as it heats and cools. Should air enter, the overflow reservoir no longer will replenish drops in radiator coolant level.

 

Yep my black plastic cover has the screw broken in that area now so I just lift it and unscrew the cap. I am confused if the overflow reservoir works or just sits there.

Alls I can say is that's my experience. It had a pretty bad leak I had to add a lot of fluid, but after that it was OK. I had not purchased the extended warranty so I was trying to see if I had to replace. At the time many with extended warranty had it replaced free.

 

When the coolant in the engine and radiator is heated it expands pushing coolant into the overflow reservoir. When it cools the coolant contracts and draws coolant back from the reservoir that is slightly pressurized.
The system is sealed by a pressure cap on the reservoir with a one way valve to allow air into the top of the reservoir. If the coolant pump bearing leaks coolant under pressure when the system gets hot no coolant is pushed into the reservoir it leaks from the bearing instead.
When the coolant cools and contracts there is no pressure in the reservoir and air is drawn into the system through the same path that the coolant escaped through.
The one way valve in the pressure cap needs a small vacuum in the reservoir to open it and let fluid into the cooling system. This vacuum cannot exist if there is a leak in the system.
So the system looses coolant but the reservoir does not top the system up. This design is common to all vehicles that I have seen, but the simple addition of a second connecting hose to the reservoir would overcome this problem as long as the reservoir was above the rest of the system.

John (Britprius)

 

i wouldn't say most gen II's need a pump by 80,000 miles. it's difficult to put a number or percent on it when all you read here are people who need it.

 

Ha, my 2007 Prius's ICE water pump had a bunch of "pink ice salt" deposits on the inside of the pulley and my ICE coolant level was slightly low. I also topped off (pulled off black plastic cover, radiator was FULL), cleaned the deposits off the pulley, and kept on driving. That was ~6-7 months ago, 7000 miles have been driven and it hasnt leaked since! I suppose I get to join the (short-term) "add coolant to a leaking ICE water pump and keep motoring" club!

When the time comes, I fully intend on replacing the pump myself. It looks super easy, compared to some water pumps I've replaced in the past!

 

I need to replace my water pump bearing Prius guy 32, what instructions are you looking at?

 

Here's a good video on youtube.

 

That is very easy !

 

That was exactly what I needed JC91006, thank you. I've got the part I need and I'm replacing it today.

 

If you have never replaced the belt, I am pretty sure that needs to be done. But, I am wondering what makes the dealer think the water pump needs to be replaced? If it is not making a noise or leaking, I would not mess with it.

Mike