Identifying leaking EVAP hoses

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by azchris, Apr 9, 2020.

  1. azchris

    azchris Junior Member

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    Hi all,

    Recently I started caring for a 2008 Prius with a check engine light lit up. Apparently it was taken to the dealership about a year ago and they diagnosed a P0441/P0455 Evap Emission Control System Leak (work order says Gross Leak Detected). From what I know the leak was pointed out to be behind the gas tank but the quote was pretty significant so the work was declined at that time.

    I pulled the codes myself and didn't see any new ones - just the P0441. I got under the car and found two lines appear to be chewed up. One of them is coming from the purge flow switching valve (which I assume is causing the code) and the other one seems to be connected to the gas tank itself. I was hoping to identify what the other hose does, part numbers or hose size for both of them, and what's involved with replacing them. It seems like a $10, 10 minute job so I'm wondering if I'm missing something that the dealership knew at the time or if they were just quoting an excessive amount of labor.

    These were all taken from the back of the car behind/slightly above the gas tank. Here's the purge flow valve hose which definitely has a huge tear in it:

    [​IMG]

    Here's the other hose that appears to have marks on it, but I can't tell if it's actually leaking. I have no idea what this is, but it seems to go straight into the tank:

    [​IMG]

    Here's a picture of them both from further back for context:

    [​IMG]

    I've never seen this many hoses attached to a gas tank in my life. Please help.
     
  2. ChapmanF

    ChapmanF Senior Member

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    Evaporation control systems are complicated, no two ways about it. If you look under the technical library tab on techinfo (more info), you can find Toyota's technician training materials and the whole section on evap systems. Makes it a lot clearer than just what's in the repair manual.

    Finding the hoses should be possible browsing through the illustrations at parts.toyota.com or most of the dealers that sell online. The one thing that makes it tricky is that nobody knows what the people are smoking who decide what categories the different illustrations go under. Sometimes you have to guess three or four times. IIRC, there are fuel-related diagrams under engine or fuel system but also some under body, and maybe someplace else too.
     
  3. ILuvMyPriusToo

    ILuvMyPriusToo Senior Member

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    Looks like one of those is missing a pinch ring too. Please let us know how your repair goes!
     
  4. azchris

    azchris Junior Member

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    Thanks for the tip! I was able to find it on that site. Looks like the part is 7774047050 - vapor canister assembly which is a $319 part.

    Unfortunately I called the parts desk at my local dealership and those hoses only come with the complete vapor canister assembly, which now makes sense as to why the initial service estimate was high. So now I'll have to see if any of the parts stores that are still open have matching hoses they can cut for me...
     
  5. azchris

    azchris Junior Member

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    If you're talking about the first pic, I removed that one right before taking the pic. If it's somewhere else, I might be missing it... :cautious:
     
  6. Elektroingenieur

    Elektroingenieur Senior Member

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    Correct; see Figure 77-01, Fuel Tank & Tube, part name code 77740; be sure to click View More Images. (If the images are broken, try again later.)
    That’s another disappointing thing about parts.toyota.com, and I think it comes entirely from SimplePart’s processing. The original Toyota catalog uses only four groups: Tool/Engine/Fuel, Power Train/Chassis, Body, and Electrical, so I did the same in my own software, which I regret I can’t share.
     
  7. azchris

    azchris Junior Member

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    Got it fixed up - went to an industrial hose store and they gave me a few inches of the closest match they had as a free sample. Cleared the code and ran a few errands in the car and it hasn't come back on. I only swapped the smaller hose with the obvious hole, if it comes back someday I'll see if I can wrangle the larger hose out of there.

    Next thing to tackle is the cluster dying intermittently, which after searching here is apparently a notorious issue with these cars... Anyway, thanks everyone for the help!
     
    PapaWill and ILuvMyPriusToo like this.
  8. dolj

    dolj Senior Member

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  9. PapaWill

    PapaWill Member

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    Any codes or lights back on or did the swap of the hose fix the problem? I have the same codes and not sure where to start. Thank YOU! azchris.
     
  10. azchris

    azchris Junior Member

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    Unfortunately there did end up being a hole in the larger hose as well which eventually caused the code to return, and as much as I tried I could not wrangle it out of there with the tank still attached to the car. My plan was to drop the tank (there are a bunch of videos on youtube, it looks pretty straightforward to do in the driveway) and swap the entire evap canister with an ebay junk yard part, but we ended up getting rid of the car for a 2020 model for unrelated reasons, so I never got to play with it.
     
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