Serpentine Belt

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by N3FOL, Nov 21, 2014.

  1. N3FOL

    N3FOL Member

    Joined:
    Dec 2, 2007
    891
    16
    0
    Location:
    Stewartstown, PA.
    Vehicle:
    2008 Prius
    I have a 2008 and mileage is just a tad over 100K. Do I need to replace the belt now or at 120K. Is there any documentation anywhere as to how to replace and adjust the belt properly?
     
  2. GregP507

    GregP507 Senior Member

    Joined:
    Apr 5, 2014
    3,002
    478
    0
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    For what it's worth, I'm not a fan of replacing things based on age alone (myself included), but I'm not a mechanic or a dealer, so I don't have a vested interest in recommending that something be replaced when it's not necessary.

    I'd look for any of these things before I'd go ahead and replace it:
    • Squealing sound: Belt slipping
    • Chirping sound: Misalignment of an accessory drive pulley
    • Frayed belt edge: Misalignment of an accessory drive pulley
    • Polished belt edges: Belt slipping
    • Glazed belt grooves: Belt slipping
    • Fluid contamination: Oil, power steering, or coolant leak
    • Excessive cracking: Other than severe old age, defective tensioner
    • Whirring sound: defective bearing in tensioner pulley or idler pulley
    • Rhythmic noises occurring at engine speed: Delaminating belt backing, chunking of belt ridges, or foreign object embedded in belt groove
    • Grinding sound: damaged bearings in driven accessory
    • Belt coming off: Pulley misalignment, belt misalignment on pulley, defective tensioner, or bearing wear in tensioner, idler or driven accessories
     
    #2 GregP507, Nov 21, 2014
    Last edited: Nov 21, 2014
    Prius_Angie likes this.
  3. uart

    uart Senior Member

    Joined:
    Sep 7, 2009
    4,215
    1,185
    0
    Location:
    Australia
    Vehicle:
    2005 Prius
    I think the recommended schedule is 120k miles, but you can inspect it and see if it looks healthy. Most people who have changed them notice lots of small cracks in the rubber when you look closely, but the cords and overall integrity are usually still good at 120k miles.

    I changed mine at about 125k miles (200,000 km) and wrote a bit of a guide here: V-belt and plugs, 200,000 km maintenance. (pictures) | PriusChat

    The main problem that people seem to have with this job is loosening the pulley wheel bolt. So do make sure you've got the right tool for the job and don't round it off. The rest of the job is pretty easy.
     
    Prius_Angie likes this.
  4. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,478
    1,540
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    I do preventive replacement of the ICE water pump every 150k miles (concurrent with the coolant refresh) and replace the serpentine belt at that time as there is no additional labor cost and the belt part cost is minimal. Only done once so far as my 2004 Prius is only at 265k miles. :)

    JeffD
     
  5. N3FOL

    N3FOL Member

    Joined:
    Dec 2, 2007
    891
    16
    0
    Location:
    Stewartstown, PA.
    Vehicle:
    2008 Prius
    The belt still looks good at 100,135 miles looking at it. I appreciate your input on this. When the weather temps gets a little better, I might go ahead and replace the belt. I will assume my 2nd gen prius does not have an auto belt tensioner pulley not like my old SHO. I'll go ahead and check your link regarding belt replacement soon.
     
  6. N3FOL

    N3FOL Member

    Joined:
    Dec 2, 2007
    891
    16
    0
    Location:
    Stewartstown, PA.
    Vehicle:
    2008 Prius
    Hello uart. I've seen your link on the write-up. Thanks for taking the time to do that.

    My question is on the idler pulley 'B'. Is it necessary to loosen the bolt and simply loosen the belt by turning 'C'?
     
  7. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    2,002
    739
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    Yes bolt B is the one that locks adjustment and makes tensioning pulley straight. Bolt C adjusts the tension (if B is lose) but tension will get bit tighter when you tighten bolt B.
     
  8. exmetrodriver

    exmetrodriver Member

    Joined:
    Jun 27, 2014
    124
    15
    0
    Location:
    Puget sound, Wa.
    Vehicle:
    2005 Prius
    Model:
    II
    I did mine at 130K when I purchased the car. Kind of a no brainer to me for a 8 dollar part at that mileage. Here's a good link:

    Belt change how-to with photos | PriusChat

    I also found some stuff on youtube that might help you. It was 30 minutes max and I'm no mechanic.
     
    Prius_Angie likes this.
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,181
    6,288
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    I suggest you inspect the engine coolant pump to make sure the bearing is not seeping coolant. If it is, the pump should be replaced when you replace the serpentine belt. My post below explains how to do that.
    How to replace engine coolant pump and thermostat | PriusChat

    Use a quality 14 mm, six-point socket on the idler pulley nut. Use an extension on the cheater bar as needed for leverage.

    You are correct that the Prius does not have an auto tensioner pulley, you need to adjust the tension manually when you install the new belt. The tension on a new serpentine belt is adjusted so that 22 lbs of force applied to the longest run of the belt results in 0.4" deflection.

    The cracks are going to be on the inner surface of the serpentine belt so you need to remove the belt to see them.

    When you look at the outer surface of the belt, you will probably notice that the rubber is getting shiny/glazed. Compare the appearance to a new belt. That results from the belt's outside surface slipping on the coolant pump pulley.

    An excellent idea to replace the belt in the spring when ambient air temps are pleasant.
     
    #9 Patrick Wong, Nov 23, 2014
    Last edited: Nov 23, 2014
    SteveLee likes this.
  10. Oldwolf

    Oldwolf Prius Enthusiast

    Joined:
    Feb 15, 2011
    805
    105
    0
    Location:
    NC
    Vehicle:
    2016 Prius v wagon
    Model:
    Four
    Thanks for the great thread. My 2005 has 77k on it now. The belt looks good, no weeping at the bearing, so no belt worries it seems.

    - Galaxy S5
     
  11. Oldwolf

    Oldwolf Prius Enthusiast

    Joined:
    Feb 15, 2011
    805
    105
    0
    Location:
    NC
    Vehicle:
    2016 Prius v wagon
    Model:
    Four
    81000 on the '05 G2 now, serpentine belt still looks good. No reason to change it yet I guess.
     
  12. phdchp

    phdchp Junior Member

    Joined:
    Jun 7, 2009
    27
    7
    0
    Location:
    Birmingham, AL
    Vehicle:
    2008 Prius
    Model:
    N/A
    My wife's 2008 has 137k miles on it with the original belt. I started getting nervous about the belt breaking and leaving her stranded. After reading the great instructions in this post, I decided to tackle the job myself. I bought the new belt at the Toyota dealer in Bimingham, AL for $20. After getting my tools together, it took me between 15 and 20 minutes to get it done. Fortunately, I have a slender arm to get between the pulley and the frame so I did not have to crawl under the car. One of the easiest jobs ever! Thanks for all the good posts that gave good information. The old belt did have cracks in it, but it would have lasted longer. But for $20, I do not have to worry about it. The Prius has got to be one of the best cars ever!!
     
    Prius_Angie likes this.
  13. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    15,110
    7,752
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2010 Prius
    Model:
    V
    At 137k miles, I would've tackled the water pump at the same time
     
  14. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    9,498
    4,444
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Thinking about mine also at almost 90K. Wife's car don't need to leave her stranded. I bought an OEM belt on eBay for $8. Took about 2 months of casual perusing to find one.
    Part number: 90916-02570

    If u have the time best to buy it online much cheaper.

    I like the auto tensioner on my Crown Vic. One of the few things Ford did right. On this car best to install it just snug and put the car in Inspection Mode and let it idle for about 15 mins and then go back & tighten it to spec. It will have broken in a little.
     
Loading...