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C1202 brake reservoir low

Discussion in 'Gen 3 Prius Technical Discussion' started by Radiospank, Feb 10, 2024.

  1. Radiospank

    Radiospank Member

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    Hey, so I got this code and realized it was brake fluid reservoir being low so I filled it up and months later it’s low again and code is back. So obviously there’s an issue because the reservoir shouldn’t be getting low.

    I don’t spot any brake fluid leaks on brakes, I did change the abs accumlator and brake booster before but with used eBay parts.

    I haven’t done any inspection of those parts yet but just want to get your thoughts on what it might be.

    Also still on original front and rear pads at 170k miles
     
    #1 Radiospank, Feb 10, 2024
  2. bisco

    bisco cookie crumbler

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    All you can do is look over the whole brake system, it has to be leaking somewhere.
    Definitely start at the reservoir and actuator
     
    #2 bisco, Feb 10, 2024
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  3. Radiospank

    Radiospank Member

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    Hmm, yea looks like I got to take off that top bonnet, not too bad but was just putting it off.
     
    #3 Radiospank, Feb 10, 2024
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  4. bisco

    bisco cookie crumbler

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    Feel underneath everything you can for moisture,
    How long does it take a full reservoir to empty?
     
    #4 bisco, Feb 10, 2024
  5. Tombukt2

    Tombukt2 Senior Member

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    If it's leaking at the actuator or the other part you have a generation 3 you should be able to shine a bright flashlight and Milwaukee LED comes to mind and you should be able to see shiny brake fluid standing somewhere on those two components if in fact It's weeping or dripping I would think not unless you left a ferrule loose. What I would more suspect is something happening at a caliper or a wheel cylinder and it's time to probably have a good look with the wheels off or you can see both sides of the caliper and brake assembly fairly easily brake fluid just can't be vanishing into the system can't get sucked into the engine and burn up or any of that stuff so it has to be going somewhere how much are we talking about a quarter inch or something below the full line?
     
    #5 Tombukt2, Feb 10, 2024
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  6. Radiospank

    Radiospank Member

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    On 11/29/23 I refilled the reservoir so maybe 2.5 months till now
     
    #6 Radiospank, Feb 10, 2024
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  7. Radiospank

    Radiospank Member

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    Hmm no it gets the low mark and below I believe, I will definitely do some deep investigation today and take a look at the actuator and abs accumlator because I replaced both of those on 11/22/21
     
    #7 Radiospank, Feb 10, 2024
  8. bisco

    bisco cookie crumbler

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    2 1/2 months might be a slow enough leak to make it difficult.
    Any stains on the ground where you park?
     
    #8 bisco, Feb 10, 2024
  9. Radiospank

    Radiospank Member

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    Not that I noticed but I park on the street and it’s dark so perhaps I don’t notice it. I’ll try Parkin in my driveway from now on and see if I spot anything, but I’m also going to look into this today so maybe I’ll find something
     
    #9 Radiospank, Feb 10, 2024
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  10. Radiospank

    Radiospank Member

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    So I did indeed see some fluid under the car about where the abs accumulator is. After inspecting the actuator and accumulator I noticed a little bit of fluid, very minor and was almost residual. Anyway, I checked the actuator and that seemed perfectly fine and no leaks on any threads and so I believe it’s the abs accumulator.
     

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    #10 Radiospank, Feb 10, 2024
  11. CR94

    CR94 Senior Member

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    Could it be leaking where the hose clamp is backed off the nipple, as seen in your IMG_4788.jpg?
     
    #11 CR94, Feb 10, 2024
  12. Radiospank

    Radiospank Member

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    yea i noticed that too lol, i guess i never put it on correctly, but i also didnt notice any fluid around that part so I dont think it was that. anyway i did affix the clamp correctly and put some paper towels around that area so ill check it in a few days to see if it soaks up any fluid.
     
    #12 Radiospank, Feb 11, 2024
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