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Dirty Brake Fluid After "Flushed, Bled Complete Brake System"

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by tnt01prius, Aug 25, 2022.

  1. tnt01prius

    tnt01prius Member

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    Had the hydraulic brake actuator replaced, and "complete brake system flushed and bled" on my 2005 Prius. ($75 plus kit $23). Brake fluid in reservoir looked clean/new as it should. A year I replaced front brake pads. After pressing the caliper piston (?) somewhat to slide over pads I later noticed the brake fluid in the reservoir was back to dirty. Should that happen after a true flush and bleed service? Does it necessarily indicate a less than thorough flush and bleed? What can a guy do after more than a year later? Ideas?
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    That was the total cost? Dealership did it?

    I’m not really familiar with second gen, but thinking “brake actuator” is about a grand new, salvage would be in the hundreds. And the job is not trivial.
     
  3. ChapmanF

    ChapmanF Senior Member

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    For exactly that reason, there is a school of thought that prefers to open the bleed valve on the caliper, let the gunky fluid escape there while shoving the piston back, then close the bleed valve and add the comparable amount of fresh fluid to the reservoir.

    The lines out to the calipers are dead ends and the fluid there gets old and gunky, and isn't necessarily stuff you want to backfeed into the $$$$ brake actuator.

    Maybe it is surprising to have it be visibly gunky so soon after a "flush" ... but if the bleed valve had been opened, it wouldn't even have been an issue.
     
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  4. Tombukt2

    Tombukt2 Senior Member

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    Wow I've never seen a gin too so far with nothing other than a pretty much clear reservoir unlike all my Corollas and everything else all the way back to cars with wet hydraulic clutches those master cylinder reservoirs were always black. because the glycol fluid was eating up the old timey rubber. Nowadays they have advanced polymers and fancy o-rings that don't get eat up.
     
  5. ChapmanF

    ChapmanF Senior Member

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    Fluid from the calipers in my Gen 1 got sort of blackish. I think that was still from the rubber seals.
     
  6. tnt01prius

    tnt01prius Member

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    Oops, the ($75 plus kit $23) is for the "complete brake system flushed and bled" only. I mentioned the actuator replacement for context.
     
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  7. tnt01prius

    tnt01prius Member

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    Thank you Chap. Silly me. I thought I had paid for that bleeding at the calipers with the $98. "complete brake system flushed and bled" job and I was good to go. So, could the gunk have built up at the calipers in the year long interval since the job was done?
     
  8. rjparker

    rjparker Tu Humilde Sirviente

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    It is certainly not your fault although some might make you think that way. Bottom line, I would take it back and ask them to do it again. Referencing Priuschat won't help at all but a positive attitude with a known service adviser should at least net a discount.
     
  9. ChapmanF

    ChapmanF Senior Member

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    My answer to the last part is "I don't know, exactly. I have seen it look blackish coming from calipers, suspect that's related to the rubber of the seals, and I'm not sure how long it takes to look noticeable."

    For the first part, I think you did pay for bleeding at the calipers, and maybe they did that, and maybe they didn't.

    But that's not the "bleeding at the calipers" I was talking about. I was talking about a year later when you pressed back the caliper piston to fit over new brake pads.

    If you follow the easy practice of always opening the bleed screw when you do that, then you never backfeed fluid from the caliper back up to the $$$$ brake actuator, whether it's fresh or old, gunky or clean.
     
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