Change water pump without draining coolant from bottom?

On my Gen 3 two of them I haven't changed or removed the coolant to change the pump yet You need to take the plastic off of the intake manifold that snorkel that auntie noise making business the what is it for 10 mm screws the long ones that hold the air box in the hose on the throttle body and the thing that extends over to the passenger side of the car that looks like the stock of a gun almost or a rifle that all lifts out of the car once that's out of the car you're standing there looking at your water pump I usually at the time I'm doing this really don't care about the coolant I just said a pan like the kind you mix concrete in at the construction site under the front end of the car I'm after Jack a couple of pumps on the jack to slide that big plastic container under the Prius the wheels won't come off the ground it'll just be enough so the pan slides In reality where I live I'm out in the country on dirt I just undo the hose coming out of the back of the water pump and let the little thing run on the ground via my under shield and it just runs out because I've got plenty of coolant so that pretty much eliminates the draining portion now I just undo the bolts on the water pump unplug it pull it straight up have a look at it I usually take the black plastic off the back of it pull out the impeller see that it's all starting to fall apart and then either replace the impeller buy a new pump or have one at the ready put it on install it replace my hose that I have on clamped and sitting to the side and the coolant's draining out of now it's empty put that back on fill the reservoir slowly and I do mean slowly and then put it up there on that what is it b Mark above full think it's b milk the hoses like a milk and a cow because I'm down there at the lowest hose in the system the big fat one on the back of the pump squeeze squeeze squeeze squeeze like you mean it check your level in your degas bottle again. Make sure you're at that mark above f now start the car let it run I've never used maintenance mode personally I just turned the car on and sit there with my foot on the gas a few minutes back it up in the driveway if I want whatever I've already pulled the pan from underneath and let the jack down and all of that so my driveway is enough room where I can drive the car backwards and turn around and just do whatever while it's running and things are happening You can also command up the water pump if you have tech software plugged up to the car and generally make things move around in the water system within a few minutes everything will get right and you'll move from the b mark to the full mark if it's below that you want to top it up after you think you're done turn the car off leave the lid off the jug or the bottle go in the house and wash your hands and take your time for a few minutes and let everything just stand give it 20 minutes or so You shouldn't be in any big hurry and then when you come out with clean hands and everything good to go look at your bottle look at your connections on your pump Make sure you don't see any leaks or funny business now you can put your plastics all back in and what have you to make the car run while I'm adjusting the levels I just have the top of the air box plugged up to the plug it needs to be plugged up to and all that for the car to run nicely I don't have the tube and the bottom of the air filter box in because that's out while I'm removing the pump now I just flip the lid of the air box on top of the valve cover and install the lower part of the air box and the snorkel and all of that but the filter back in replace the top of the air box put the clips on You should be finished.

 

You’re talking about the pump on the engine coolant circuit, not the inverter coolant?

The drain for that is a spigot on the bottom of the radiator, reachable by hand through a cut-out in the engine panel. While it’s technically reachable without raising the car, I’ve found I had to get it higher a few inches, or I just couldn’t get the leverage to break it loose. And just off the top of my head, I don’t think you can say clamp something off and avoid a spill. Myself I would do it in conjunction with a coolant change, probably will do next at the next change.

if you’re committed to DIY’ing it I can post some repair manual excerpts in a bit. Still, no offense meant, just concern: if you’ve no means to raise the car, is that just due to your current location, or? Are you ok doing oil changes for example? I’ve done more oil changes on ours than I’ve got fingers and toes, but have never done a water pump on a car. I’ll get it done but it does seem a bit more daunting.

have you got the replacement pump btw? Direct from dealership parts department, or? It’s an Aisin brand, WPT190 if i recall correctly. You want to be careful with the purchase; there have been reports of counterfeits, or maybe it’s people selling rejects/returns. Would be good to replace the adjacent thermostat as well; not sure of the part number on that. Check with dealership parts department for both, and you could look up online. Amayama is good source.

Consider getting dealership service department to do it, in conjunction with a coolant change, get a quote? Try several if practical?

 

When you remove the engine coolant pump, the fluid WILL spill out.
The only way to stop that is to turn the car over on it's left side.
Since that is not practical... you'll have to raise the car, or it will be
extremely difficult reaching the bolts because there isn't much ground clearence
under the Prius.
It might be worth it to invest in 2 good jack stands, ramps and jack.

 

Here's the cost for me, through Amayama, in CDN dollars, on west coast of Canada. The thermostat is available cheaper from UAE (United Arab Emirates), but then I'd incur two shipping charges:



(Roughly $172 USD, all-in)

 

First, I would not change it unless you can safely contain the antifreeze which can kill pets and other animals who like the taste.

However Tom’s strategy above might catch most of it and you could clean up the rest.

In reality I would not do the job unless I was willing to safely jack it up with jackstands properly placed and with wheel chocks installed on the rear wheels. There is some risk working under a car and a shop’s lift makes it easier, safer and quicker.

If you do simply dump the antifreeze you need to use the proper Toyota coolant to replace it. Which costs about the same as two jack stands if you shop.

There are some theories floating around suggesting old or incompatible coolant could erode head gaskets and cause failures. This is conceivable and perhaps just as likely as a clogged egr causing a blown head gasket on gen3s.

In fact changing coolant is way more beneficial than proactively replacing an oem water pump. Coolant change is required by Toyota around 105,000 while pump or egr maintenance is not listed by Toyota. Plus counterfeit oem pumps are clearly more risk than leaving an oem pump installed.

I would have a local shop install an oem pump, change the coolant in both systems and run a flow test on the egr.

 

It is not oem and could be counterfeit or a manufacturing second. For $143 I would return it and get the real thing. Toyota Part 161A0-29015. The lowest price I find from online Toyota dealers is $240.

From Aisin Reviews

Concerning coolant:

Concerning quality:

 

Those are European lives they have them in garages in Europe right regular used one many times they are great to turn the car on its side they even have rotisseries better make sure everything in the car is secure when you roll it around
.

 

Actually my counterfeit generation 3 water pump has been installed three different times I also have two used factory pumps that I guess haven't heated enough and split the impellers they work perfectly and I've had to swap them out of other cars to get the other cars running and workable so on so my counterfeit is actually run pretty good but it's not sat in the car for a super long time or a lot of mileage yet but oh well usually the impellers fail on these and they feel like they're locked up or stuck just take it apart pull the impeller out you'll see the problem It's possible to buy impellers 25 bucks or something like that I think they all split and do the same thing it's not a aftermarket cheap business the original one you're taking out is splitting messed up. That's why you're taking it out.

 

You got the Aisin WPT-190? You may be returning a perfectly good pump, exactly what a Toyota dealership will sell you, for a hundred bucks more. There have been counterfeits, and maybe sales of factory rejects, so it is a bit iffy. Just food for thought

Post #6 is a screenshot of my current Amayama cart, what I'll likely be buying in a year or two. I've got quite a few small items through them, never any issues.

 

When it comes to a water pump, I would leave my OEM pump in for 305,000 miles (which I have) rather than risk a counterfeit or second.

I would tend to believe the reviewers who actually bought the suspected unit. Or keep my original.

The trick is to monitor your engine temp so you have some idea when the coolant is on its way up to 248f before it gets there and trips the light. Change the coolant as well. Ten times so far in my case.

 

Suppose Aisin manufactures 100 water pumps, and sells 50 of them to Toyota for dealerships to sell you. The other 50, they grind Toyota's logo off of, and sell into other distribution channels for you to buy for a hundred bucks less.

Are they deciding which pumps go where by flipping coins?

 

The way I read the OP’s post he is proactively, before failure, taking out a good oem pump.

I would much rather leave the known good oem pump than replace it with a pump others have bought and had fail quickly. Sure you could get lucky and get a fairly good one but the downsides are big.

We know “no name” aftermarket egr valves, maf sensors, wheel bearings and water pumps are unreliable. We see Amazon reports of Aisin water pumps with the Toyota name ground off quickly failing. We know counterfeits are out there with Toyota packaging, most commonly on eBay and Amazon who simply refund your money on failure but don’t police their marketplace.

Do we hear of new Oem pumps or almost anything from the dealer supply chain failing? No. If I change an oem pump it is with another oem pump.

 

Good question.

Is Aisin so incompetent, as to have a 50% (for example) failure rate? Or to have the resources to be testing/rejecting them, one by one?

I’m thinking to swap in the Aisin pump at my next coolant change. Our miles are very low, and the pump that’s in there likely viable for a good time to come. I’ll hang on to it and see how it goes.

I suspect there’s a few defective Aisin WPT-190 (either failed inspection or found defective and returned by customers), coming from a few irresponsible vendors.

I’ll more’n likely buy through Amayama, see how that goes. So far that’s worked out for me, most ambitious purchases being components for conversion to spin-on oil filter.

 

They are inspecting them to ensure Toyota does not get defective units.

 

Clearly I used 50 and 50 to make the question simple. We don't know what proportion of their production run gets sold to Toyota and what proportion undergoes logo-grinding and alternative-channel sales.

I could have made up five-sixths to Toyota and one-sixth to logo-grinding, and asked if the decision is made by rolling a die. That might have been closer to the actual proportions, whatever they are, but wouldn't have changed the essence of the question, and it seemed simpler with the coin.

Most manufacturers will devote the resources that are needed for a QA program sufficient to make sure they're filling their customers' orders with products that meet their customers' specs.

To me, it would seem odd if they were diverting some fraction of their production to alternate outlets with the customers' logos ground off, without having their QA results somehow involved in that process.

 

When I buy a WPT-190 pump, I suspect there won’t be a ground-off Toyota label. Time will tell.