1. Attachments are working again! Check out this thread for more details and to report any other bugs.

ICE water pump replacement - Gen II

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by jadziasman, Jun 22, 2013.

  1. jadziasman

    jadziasman Prius owner emeritus

    Joined:
    Jan 17, 2011
    1,355
    486
    0
    Location:
    District 6
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    I replaced the engine water pump this morning on my 05 Prius after 198650 miles. It was making a loud grinding noise and sometimes it made other strange noises too.

    I bought an Aisin WPT-111 water pump that comes with a metal gasket from Rock Auto ($45 shipped), a gallon of SLLC I purchased at a local Toyota stealership ($22), and a Lisle spill free funnel kit from Amazon ($26 shipped).

    I found a youtube video showing how a Toyota dealership mechanic replaced a 2006 Prius ICE water pump. It doesn't show every detail IMHO but it's still pretty instructive.

    I drove my Prius up onto ramps and raised the back end with a floor jack and stands to level it out so I could get underneath easily to access the engine block drain. I did an oil change too while the car was conveniently up in the air. Actually I changed the oil before starting the car in inspection mode to bleed the cooling system later in the morning.

    The toughest part of the job for me was removing the 10 mm water pump pulley bolts. Patrick Wong apparently was able to loosen them by keeping the drive belt on and maybe tightening the belt a little. This didn't work for me. No matter how tight the belt was, the water pump and idler pulleys still rotated when I tried to break the bolts loose.

    I ended up removing the purge valve like the video shows and used the wood handle of a small tack hammer with the top removed and wedged the hammer shaft between the belt on the idler pulley and the frame the idler pulley attaches to. When you remove the purge valve, there's a small opening beneath it that you can wedge something to prevent the pulley from rotating. The 41 second mark of the video kind of shows where to wedge something. The pad the purge valve bolts to is clearly seen in the center of the image as a white circle with a hole in the middle. Just underneath it is a space to put the wedge.

    The mechanic took the belt off before loosening the water pump pulley bolts. I left the drive belt on. The mechanic used a pair of large channel lock pliers to hold the pulley. I didn't like that idea too much so I had to improvise when the pulley bolts wouldn't loosen easily.

    The 10 mm bolts on the water pump loosened easily enough but they are difficult to reach. Not much space to work from the top of the engine compartment. Even tougher with a six point socket. I could have used a 12 point, but I didn't want to strip the bolt heads if they didn't break loose easily. Fortunately the bolts loosened easily (whew!).

    I opened the engine block drain and eventually a little more than 3.2 quarts slowly came out . I drained the coolant while I was loosening the water pump bolts.

    Even though I drained the block first, there was still a lot of coolant that gets released through the water pipe behind the water pump when I took the pump off the block. I'd guess about a pint or so gushed out. I put enough shop towels underneath to soak up the coolant beforehand. I'm pretty sure that the thermostat kept the coolant in the radiator from spilling out. I didn't work on the water pump until the car sat overnight so that the coolant was completely 'cool'.

    I installed the new pump and gasket and tightened them with the 1/4" drive ratchet. I don't own a torque wrench small enough to fit in that narrow gap so I had to guess how much to tighten. Same for the water pump pulley bolts. I wedged the wood hammer handle again between the idler pulley and its frame again to tighten the pulley bolts. I figure I'm not going to be able to produce too much torque with a small 1/4" drive ratchet like the one the Toyota mechanic used.

    The video doesn't show the mechanic draining the block but I did so that I could do at least a partial change of the SLLC. I didn't want the hassle of dealing with draining and refilling the thermos bottle so I clamped off the hose to the thermos and I clamped off the heater core exit to keep the coolant in each "container". I also liked the fact that I didn't need to take off any of the plastic panels underneath the car.

    It really helped to have the Lisle spill-free funnel. Refilling what drained out and bleeding only took a total of about 15 minutes. It went pretty much like the video showed, Open the bleeder screw on the top of the radiator and attach a hose to the bleeder to collect the coolant while bleeding the system. The coolant re-enters the engine block pretty quickly - less than five minutes for 3 quarts of new SLLC. Starting the car in inspection mode completes the bleeding process - during that time, the cooling system draws in the remaining pint and the rest of the air remaining in the cooling system is expelled from the bleeder.

    I drove the car for a few miles today in 90 degree heat. I didn't hear any coolant sloshing around anywhere so I think I got all the entrapped air out. And, it's much quieter with the new water pump. Surprisingly quieter. The thermos bottle pump sounded normal too after I shut the engine off.

    So, don't be afraid to do this repair. You'll save at least $150 dollars and probably a lot more.

    2006 Toyota Prius Engine Water Pump Replacement - YouTube
     
    Yakoma, okcwxguy, koolingit and 3 others like this.
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Thanks for sharing your experience. My 2004 is coming up on 150K miles so I will be replacing the engine and inverter coolants a second time, in the next week or so. I'll also replace the engine thermostat (original) and serpentine drive belt (for the second time) as a preventive measure. I bought the Lisle yellow plastic funnel a couple of years ago and am looking forward to trying it out.

    I had previously bought a replacement engine coolant pump, anticipating I would need to replace the original - but so far the original is still working well. I appreciate your relating the need to wedge the coolant pump pulley in place prior to loosening the pulley bolts.
     
    jadziasman likes this.
  3. jadziasman

    jadziasman Prius owner emeritus

    Joined:
    Jan 17, 2011
    1,355
    486
    0
    Location:
    District 6
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    As you are keenly aware, we help each other, Patrick. You have helped many others (myself included).

    Hopefully you won't need to replace the engine water pump in your Prius any time soon. But when you do need to - man what a difference it makes!

    I learned about the spill-proof funnel here at Priuschat and found some other helpful tips here as well that increased my confidence level. The Internet age enables us to do nearly the impossible. Even though my Prius probably doesn't have too many more years ahead of it, it's still far from being a beater. So I make sure I knew what I was getting into before loosening bolts on the block. It also helps that I've removed engine water pumps before but the previous two were timing belt driven and protected from road debris and salt by the timing belt cover. Not so with the Prius water pump. It's out in the open. In fact, one of the nuts on one of the two studs was rusted pretty heavily. Soaking overnight with PB blaster might have helped loosen it this morning.

    Just so there's no misunderstanding. The wedge is placed between the idler pulley and its frame. By stopping the idler pulley, the water pump pulley is stopped as well - the belt won't turn. One thing - the water pump pulley can still rotate if the friction provided by the belt isn't strong enough - the pulley will rotate past the stationary belt. The wedge has to press down firmly on the belt to build up enough friction force on the water pump pulley from belt contact so that it exceeds the break away torque on the water pump bolt.

    I'm still surprised how much torque it took to break the three bolts loose with the 1/4" drive ratchet. It probably wouldn't have been too difficult to have made a cheater SST to hold the pulley. I would have ended up making one if my wedge idea hadn't worked. I have made a tool like this before to hold a crankshaft pulley in place while loosening the nut at the end of the crankshaft on my 92 Civic - that was a lot of fun without air tools. Axle nuts are also a real pita without air tools.

    Thirty years ago, all I could do was go to the local public library and look for repair instructions in the Motor manuals or Chilton's books or buy the service manual - which I have done the past twenty years. Who knows what the future will bring. I'm hoping for a robot that I could program to turn the wrenches for me when I celebrate my 80th b-day a quarter century from now. :D
     
    Patrick Wong likes this.
  4. bsd43

    bsd43 Member

    Joined:
    Sep 9, 2005
    130
    3
    0
    Location:
    San Francisco Bay Area
    Vehicle:
    2006 Prius
    Thanks for this thread! I just followed this and the YouTube video, and saved myself probably $300.

    I used a plain 10mm wrench to remove those 3 pulley bolts, with a 3/8" socket extension jammed into one of the pulley's holes as my "wedging" method.

    My Lisle funnel worked ok, with the caveat that it leaked until I rotated the "radiator-cap" 180 degrees -- one of the sides just didn't have tight enough of a fit.
     
  5. Rich12

    Rich12 Member

    Joined:
    Dec 12, 2012
    176
    29
    0
    Vehicle:
    2007 Prius
    Model:
    II
    Were the pump bolts hard to remove or get to? I found the pulley bolts next to impossible to budge, soaking w. PB probably would have helped as well as using a ratcheting 10mm box wrench.

    Mine was grinding like the OP reported and the mechanic said it was dangerous to drive and could fail at any moment. True?
     
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The pump's three bolts and two nuts were not too hard to get to, but I had access to both the top and bottom since the car was raised up, and the engine undercover and front passenger-side tire were removed.

    True. That sound indicates the pump bearing was falling apart.

    I'm providing a link to my post about engine coolant pump and thermostat replacement here:
    How to replace engine coolant pump and thermostat | PriusChat
     
  7. Rich12

    Rich12 Member

    Joined:
    Dec 12, 2012
    176
    29
    0
    Vehicle:
    2007 Prius
    Model:
    II
    Thank you, Patrick. I wish I would have had time to research and collect the right tools before attempting this the first time. I was panicking about the necessity of the repair and being January didn't help any. Why can't pumps fail in June?

    But I was able to replace the serp. belt myself at a total cost of $9.63. Dealer wanted $35 for the belt alone. God knows how much they would charge for spark plugs+labor!
     
    Freeus5 likes this.
  8. Rich12

    Rich12 Member

    Joined:
    Dec 12, 2012
    176
    29
    0
    Vehicle:
    2007 Prius
    Model:
    II
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Yes, this is why my repair philosophy is to try to anticipate failures and take preventive measures where appropriate.
     
    Freeus5 likes this.
  10. bsd43

    bsd43 Member

    Joined:
    Sep 9, 2005
    130
    3
    0
    Location:
    San Francisco Bay Area
    Vehicle:
    2006 Prius
    The pump bolts themselves weren't hard to remove, but they did require some contorting to get both hands in the area -- one to guide the socket and one to move the socket wrench. A ratcheting wrench wouldn't have really helped -- once the bolt/nut is loosened slightly, the rest is cake.

    As long as the pulley itself is forced to not rotate, I found that the pulley bolts weren't horrible to remove either. (I only accessed via the top.)

    It was 72 degrees and windless when I did the pump on Saturday -- warmer than our usual June weather here in the Bay!
     
  11. Twistalime

    Twistalime Junior Member

    Joined:
    Apr 23, 2015
    3
    1
    0
    Location:
    Columbus, Ohio
    Vehicle:
    2006 Prius
    Model:
    Three
    After much research and watching several videos, I tackled the water pump and serpentine belt replacement on my 2006 Prius (with 126,000 mi) about a week ago.
    There had been a noise coming from the right front side of the ICE and then coding P1121 eventually.
    I will preface the next part by saying I've been out of work for over a month. Money has been tight and the last thing I wanted to do was spend money on an auto repair. I would have waited, but I had been concerned about a water pump failure and "what if" something happened to or from a job or interview.
    I won't rehash the entire process, I just wanted to give some of my insights into this process. I'm not a mechanic and I have a limited tools..

    • I purchased my Carquest branded water pump from Advance Auto online along with a serpentine belt. Cost with a coupon found on RetailMeNot saved me 30% off orders over $50, ended up being (after coupon) $42.xx.
    • If you do not have a small 10 mm wrench, save money and go to Home Depot or Lowes (or really any hardware store). Advance Auto & Auto Zone both wanted $8-$10 for a 10mm wrench (round and crescent ends, non ratcheting) but at the hardware store a mere $1.97 and a small size to fit in this confined work area. I also purchased a small set of Hex wrenches which included size 6 for the radiator bleed.
    • So when you disconnect the 12v battery negative, don't slam the hatch down. When the job is done, crawling over the flipped seats into a hot trunk to reconnect the battery isn't fun.. Lower hatch or leave open.
    • I didn't raise the car. All work from the top. Im sure there will be flack when I say this, however I did not drain the entire coolant like some have done. My theory is if it's going to leak when I'm done; I would prefer the leak occur with the old coolant than the new. I can replace with new coolant later.
    • Finding a pan to catch runaway coolant was a challenge. I used what I'm going to call a hospital wash pan. It's sort of like a shorter dishpan and it fit right under the car without clearance problems.
    • Air intake "S" hose was always in the way even though I disconnected and removed air cleaner box.
    • Reaching the lower bolts blindly with a short 10 mm (1/4 drive) socket can be done - in the future I would use a longer socket.
    • Water pump pulley.. I used a screw driver angled in through the water pump pulley and wedged under tensioner this worked well..the pulley didn't rotate. Also my water pump pulley had chunky dried layers of coolant inside. I cleaned that off.
    • Idler pulley.. I've read the challenges others experienced..I used a Kobalt 4 way wrench (rotating socket sizes on both ends of the wrench).. It happened to have a 14 mm socket and the wrench was long enough without having to add on any extension handle for extra leverage.
    • Serpentine belt had it not been for another thread posting about changing the serpentine belt in 11 minutes, I would still probably be outside struggling..
     
    Yakoma likes this.
  12. RubberToe AS

    RubberToe AS Junior Member

    Joined:
    Apr 27, 2016
    9
    1
    0
    Location:
    Oakland
    Vehicle:
    2008 Prius
    Model:
    Four
    Hi Patrick,
    I have 2008 Prius with 96K miles in good standing order. I have never changed the ICE coolant. I can see a bit of dried coolant in the water pump pulley. So based on the mileage, I am thinking of replacing the Water Pump (gasket too) and Coolant. Do you recommend replacing the Radiator Cap and Thermostat? I changed the Serpentine belt about 15K ago.
    Thanks,
    Roberto
     
  13. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Yes.
     
  14. RubberToe AS

    RubberToe AS Junior Member

    Joined:
    Apr 27, 2016
    9
    1
    0
    Location:
    Oakland
    Vehicle:
    2008 Prius
    Model:
    Four
    Thank you Patrick!! I enjoy reading your posts.
     
  15. RubberToe AS

    RubberToe AS Junior Member

    Joined:
    Apr 27, 2016
    9
    1
    0
    Location:
    Oakland
    Vehicle:
    2008 Prius
    Model:
    Four
    I've just Replaced the Water Pump and Coolant successfully on my 2008 Prius with 96K. The older water pump was leaking a bit and leaving some residue on the pulley and creating a kind of crust on itself. Although the coolant level was fine, I did not want the car to fail and potentially overheat.
    Thanks everyone for the recommendations, instructions and experiences. I used the Lisle Funnel which was great. Here are some of the steps I did and experiences I found. Many of them are similar to others with the exception of a check engine light I got when restarting the car after all work had been done.
    1. I lifted the car to unscrew and put a side the driver's side fender liner to access the thermos
    2. I disconnected a couple of connectors in the Thermos area. I think I only needed to disconnect one but I did the two.
    3. I opened the valve and gathered 6.25 quarts exactly. Based on Patrick's experience I did not have to open the other drains. this procedure left the reservoir empty. I closed the Valve after.
    4. I removed the Water Pump. I had ratchets and a small 10 mm box wrench. I wish I had an extended 10 mm wrench because I had little leverage with the small one. Anyway it still worked. Some coolant leaked at this point which was not recovered.
    5. I Replaced the New Pump and Gasket. It might be worth checking the position of the older pump before removal so that you remember its position and do the same thing with the new one. I did not do this so it took me like 5 minutes to find the correct position of the gasket and pump. I was getting tired by then.
    6. I put the screws back. I noticed that the Pump screws had some type of antiseize. Not sure what it was. I may have done a mistake but I added a bit of thread locker (the removable type). I was afraid that so much vibration could loosen up the screws at some point.
    7. I replaced the Pulley. This was a bit more difficult to tighten with the small wrench box I had. I could not torque them to specs as I could not get the torque wrench in it. So this was a best effort. I then replaced the belt and ensured it was not too tight. By the way, I had replaced the belt about 20K ago so it looked like new, no glazing or cracks.
    8. I was planning to replace the thermostat but I could not remove the hose and I was getting tired.
    8. Using the Lisle Funnel and finding the correct lid, I started filling up the Radiator. I never left the funnel empty.
    9. I removed the Relay to jump the electric Water Pump for about 20 seconds each time. I must have done it like 10 times like every 5 minutes.
    10. This process took a long time(maybe almost an hour) but I could see the bubbles in the funnel as coolant made it in. I also squeezed the hose that goes from the radiator to the thermostat a couple of times. After like 50-60 minutes, no more went in and no more bubbles, so I closed the radiator with a new cap and filled up the reservoir. By the end, almost 6 gallons went in. So I felt most had gone in and I could take it for a drive when all people were sleeping.
    11. I put the relay back.
    12. I started the car in normal mode and planned to take it for a ride at 12 am.
    13. The check engine came up as soon as I started the car. Using my ODBD2 connector it showed a code regarding coolant so I cleared it and never came back. I did not hear bubbles, possibly because the heater was at max speed and I couldn't hear them.
    14. I drove for about 10 miles pushing it and set the heater at max speed and the hottest it could. Air was coming out hot fairly quickly.
    15. Came back home and checked the reservoir level and it was fine. Let the car rest for the night
    16. Next morning, I bled the system using the bleed valve and filled up the radiator. I also opened the radiator cap while the car was off. Some coolant came out and there seems to have been some air in between sections of coolant in the clear bleed hose. The width of my hose was small so I had to heat up the hose with a lighter and expanded it with something else so it could attach to the bleed valve.
    17. I started the car and I heard some gurgles (like water flowing) but they disappeared quickly. I did this bleeding another time but the second time I did not see any coolant coming out from the valve. I then just added a tiny bit more of coolant to the reservoir and radiator they were both full.
    18. At the end 6.25 quarts went in. After 6 days of city driving, I replaced the Black Cover that goes over the radiator and declared this project a success.
    19. A couple of times, I spilled some coolant into the engine compartment when I removed the water pump and when I was refilling due to some splash. I used a water hose to wipe out all this residue.