Replacing Water Pump: Pulley Bolts Seized

Hi all, can anyone help on this?

I'm attempting to replace the water pump on my 2006 Prius (~110k miles)

I'm following the steps in this video:

and this video. I'm at the step where I remove the water pump pulley.

However, the bolts on the pulley have seized up and won't budge. What's worse is that the pulley itself is spinning so I can't apply much torque to force the bolts to turn.

I've applied two rounds of WD40 onto the bolts - one last night and one this morning. They're still not rotating.

Any advice on how to get these bolts off? Is there a better penetrant that will loosen the bolts? I'm trying to avoid going to a mechanic and paying $300-400 just for the labor on this when I'm so close to getting the job done.

Attaching a picture of the bolts and the pulley.

 

I've got around 110k on my Prius.

\The water pump has some pink residue on the outside so it has leaked at some point in the past. There is no major leak at present. I'm changing the pump and the belt, which is very cracked and will soon fail.

I tried placing a wrench on the bolt and then tapping against the wrench, but it hasn't been effective. I've been approaching the pulley and bolts from above to avoid going under the car, so there is not much room to maneuver the tools. Certainly, there is no room to apply an impact wrench.

 

Yes, most of the pink crust is blocked by the pulley in this picture.

 

Most of the pink crusty mass is behind the pulley in this picture. The picture was taken from above looking down into the engine bay, so the leakage residue is away from the camera behind the pulley.

I've applied maybe 7 rounds of WD40 by now and it still won't budge.

Next steps:
I think I'll have to bite the bullet and go under the car and remove the engine under covers to access the pulley and bolts from below.

I plan to use a long screwdriver to hold the pulley in place while I try to force the bolts to turn. (I may have enough room to place a wrench and use a hammer to tap on the wrench.)

 

Hi all,

So I ended up removing the engine under cover (RH) which gave me access to the water pump pulley from below.

Then, I was able to stick a screwdriver into the pulley holes and hold it still while I turned the pulley bolts. Once I had the screwdriver to apply resistance, it wasn't too difficult to turn the bolts.

After that, it was fairly standard procedure to replace the pump (see below).

Steps for replacement and coolant bleeding after loosening bolts.
- Removed the 3 bolts and 2 nuts holding the water pump in place
- Used a oil pan beneath the car to collect coolant after I separated the pump from the engine
- Removed the old water pump and gasket
- Cleaned off attachment point for water pump with a scouring pad

- Placed new gasket and water pump in place
- Torqued down the water pump bolts (8 ft lbs)

- Reattached the water pump pulley
- Torqued down the pulley bolts (11 ft lbs)

- Reattached the idler pulley
- Installed a new generator V belt
- Tensioned the generator V belt
- Torqued down the idler pulley (30 ft lbs)

Adding and bleeding coolant:
- Opened radiator cap
- Opened radiator bleed valve
- Filled radiator with coolant until bleed valve released coolant
- Did the "chicken dance" to get car running in maintenance mode for about 10 minutes
- Added coolant as the engine ran
- Turned off engine
- Closed radiator cap and bleed valve

Then, I reattached the bodywork I removed to access the radiator and the water pump pulley (engine under cover RH, center engine under cover, front spoiler cover, front bumper cover). I have all the bodywork reinstalled except the center engine under cover, which I'll do tomorrow. I plan try to add more coolant tomorrow, test drive the car, let it cool, and try adding more coolant again.

I think that's about all the steps. Please LMK if I missed anything.

PS. I have another question about how much to adjust the idler pulley to tension the generator V belt. I don't have a belt tension gauge, so I'm going to ask for advice on how to get the right tension in that new thread.

 

Good idea. If I ever have to work on the pump assembly again, I'll give that a try.

 

Very crusty under the water pump pulley!

 

Thanks Patrick. I also looked at the shop manual again and it explained exactly that test. I'll check the belt once my car cools down.

This morning before driving, I checked the radiator and it was still filled almost to the top of the fill tube with coolant. Drove the car across town and back on an errand and didn't get any warnings. Also didn't hear any strange sounds such as gurgling while I drove. I think I got almost all the air out of the system yesterday during the bleed.