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3rd Gen Brake Bleeding questions

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by cegeddin, Aug 24, 2023.

  1. cegeddin

    cegeddin Junior Member

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    I'm not seeing the answers to these curiosities in other threads, so going to ask here.

    I have just replaced the actuator and booster. I have everything reassembled and am about to start working with the bleeding process. I'm using an xtool d8 to do the bleeding process, which should be able to handle the techstream functions.

    The way I'm reading the manual, is if you are using techstream, you basically loosen two plugs, run through the techstream bits, and then tighten the plugs while watching the fluid levels. It looks like there's no removing of the wheels? Am I understanding that correctly?

    The second question is that the manual keeps saying "tighten the two bleeder plugs" after doing the bleed process, but I never see where it says to open the plugs, and not sure where the plugs are going to be located. I'd like to verify that what I think that means, (where the two plugs are and that. you have to open them first) before I start doing the process.

    (Attaching the document I'm looking at.)
     
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  2. ASRDogman

    ASRDogman Senior Member

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    The "plugs" are the bleeder screws on the brake caliper, which are (should) be on the top
    of the caliper. I believe it will walk you through the procedure.
    I just purchased the D8, but haven't used it yet except to hook it up to see what it looks like.
    It was pretty fast and easy so far.
    Please, update here how it went. It's time for a fluid change on mine...

    If you can raise the car up enough, you can craw under it to get to the bleeders.
    But if you can put it on jack stands, you can remove the wheels and make it a lot easier.
    Just make sure to loosen the lug bolts first.
     
  3. cegeddin

    cegeddin Junior Member

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    Thank you. That's what I thought I was understanding. I'm looking forward to doing this with the d8... The money I've saved on Labor at the dealer more than payed for it!
     
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  4. ASRDogman

    ASRDogman Senior Member

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    Got mine the middle of June. Wished I knew people near me who needed the use of it
    so I could use it! (y)
     
  5. cegeddin

    cegeddin Junior Member

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    Seems to be okay, but having a problem with one of the break lines not sealing at the ?actuator? (the thing the brake pedal attaches too.) So stuck on bleeding the FR wheel. Gotta figure out why that line is not sealing.
     
  6. ASRDogman

    ASRDogman Senior Member

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    Are you sure it's not cross threaded?
     
  7. Eddie25

    Eddie25 Active Member

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    Is it actually leaking there or is something else leading you to believe it's not sealing?
     
  8. Tombukt2

    Tombukt2 Senior Member

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    You have to look very carefully and make sure it's running out of that fitting where the fitting screws in around the tubing and squeezes on the flare for the double flare or whatever the case may be those things should screw up by hand generally speaking even when I bend them all the hell getting them out of the way when I get them correctly bent back they will thread by hand almost all the way My ranch is used for the last 1/2 inch of the last turn or something like that seriously and I don't have gloves on if this is with my bare fingers which probably have brake fluid on them by now and what have you they are very easy to cross thread You can get almost all the way to the end real easy cross threaded thinking it's just tight and if you've done that you need to squeeze down on it and make it stop I've done this once or twice If you back out of it now and take it out you will probably have a real mess you'll need the metric tap and what have you for that size I don't remember what it is by heart but the problem is is you need a blind hole tap That's the flat one not the pointed one or you'll be hitting the hole that the double flare seals up against That's your problem with the through hole tap
     
  9. cegeddin

    cegeddin Junior Member

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    I've unscrewed it and screwed it back in about 3 times. It doesn't *feel* like it is cross threaded, but if you press on the pedal, fluid squirts out from the nut. So the line isn't getting sealed one way or another. This in the line that runs to the front passenger wheel. It isn't one of the four that are together with the high pressure line, but rather the line on the passenger side perpendicular to those.
     
  10. cegeddin

    cegeddin Junior Member

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    So to repeat back, you are pretty sure I cross threaded and need to use a tap to fix it so it will seal? (But gotta be careful about the type of tap.)
     
  11. Tombukt2

    Tombukt2 Senior Member

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    Look at all the other ferules. Is the one that's leaking seated the same height as all the other ones that are not that one should be sticking out more and maybe look cockeyed? If so it's only sticking up maybe oh my God eighth of an inch possibly different when I did this on one of the ones I did a while back at that point when I noticed it was cross-threaded and buried that deep I just went on the other 8th of an inch and maybe a 16th and everything stop leaking and all the other fittings were fine so I left it alone and it's been running fine it's a personal friend's car so I see the vehicle regularly and everything is great with it If you have it crossed threaded and you back it out you might get lucky and get it to go in straight with real clean hands brushing the hole out they do make a thread chasing tool that may be able to help you out I also have some of these thread chasing tools that I got from the snap-on man Jesus a million years ago it seems like they look like the threads you're trying to clean up with a little quarter inch drive end on it so it can fit in a quarter drive tool and you offer it up by hand you get it straight and then you start hitting it with the ratchet or your drive tool and usually it will clean up the threads so you can get your ferul back in there straight.
     
  12. cegeddin

    cegeddin Junior Member

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    The ferrule is what I'm calling the nut? It is what holds the flared line snug against the master cylinder housing?

    This is the line that isn't in line with the others so it is hard to compare. It did look a little cock eyed, but it seems happy to screw back in a ways. But still spurts when snug.
     
  13. Tombukt2

    Tombukt2 Senior Member

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    Well if it doesn't stop spurting after snugging it a little bit more then it looks like you've got a problem. You can back it out clean up the threads as best you can with some kind of a thread chasing device you may get lucky and they have it at Northern tool You can Google thread chasing devices and that should show you some different kinds You're looking for one that's flat on the bottom so when it goes down in the hole it doesn't have a point that's going to try and damage the little hole and the dipped scalloped area that the Pharaoh pushes the double flare into there could also be some crap on the end of the double flare.? But I kind of doubt it cross-threading seems to probably be the case so if you can get it out clean up the threads a little bit a little gun cleaning brush that goes a long way believe it or not see what comes out of the hole when you spin the brush and bring it out slowly are you bringing any shards look like a helicoil pieces coming out if you know what those are. Basically twisted pieces of very thin metal that kind of match the thread profile if you lay them in your hand. Any of that going on you need to clean it out with the little gun cleaning brush and get all that stuff clear as possible and then offer the line up again if you have no way to chase the threads and all this kind of thing and try to be damn skippy about it and get it straight You may have to hold the line usually I try to bend the line so it kind of lays exactly where I want it to without the fair ruler the nut involved so the line will just hang there when I let it go almost perfectly with the threads ready to go in nothing been touched. You get it that close and then you can generally really pay attention to getting the thing threaded and not be trying to hold against the tension of the line trying to pull away from you or pull crooked or what have you. I hope this helps
     
  14. cegeddin

    cegeddin Junior Member

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    I appreciate it! I'm worried I have a problem gonna try a thread chaser and clean up and see what happens.

    Is it possible the flare on the line is messed up and can be fixed?
     
  15. cegeddin

    cegeddin Junior Member

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    I did figure out the threading is m10 x 1mm
     
  16. Tombukt2

    Tombukt2 Senior Member

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    When you pull it out and look at the end that seats in the hole that you're trying to thread the nut or the ferule into If the flare is damaged you should be able to tell by looking at it be all cocked over crooked silver and damaged where it scraping and making new marks if any question take one out of another car or something and cut it off so you can use it to look at but usually you can tell or some people can tell and whatever with it sitting cock-eyed like that is probably not even buried down enough on it to make the seal which is why it's spurting.
     
  17. Tombukt2

    Tombukt2 Senior Member

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    That's really 10 mm No that might be the wrench size . But I think the thread size will be much smaller like 6 mm comes to mind but a funny pitch maybe because of the brake application usually we'll get a finer thread or something I don't know I haven't looked It seems very similar on the generation too lot of the brake line fittings are almost identical so I would assume they're the same size You're using a 10 mm wrench? But anyway you may be right whatever it is it is
     
  18. cegeddin

    cegeddin Junior Member

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    The "bolt" size is 10MM and the thread size is 1mm, definitely using a 10mm wrench on is. So if I use a thread tool that is 10 x 1.0 it seems to fit. Just having a hard time finding a thread chaser versus a tap to see if that will help. The flange lap tool I rented is missing pieces and I don't think it will help.

    I cannot get this line to seal. Gonna have to think what to do next. I'm not sure what to do now.
     
  19. cegeddin

    cegeddin Junior Member

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    It doesn't *look* crooked or messed up, at least not in a dramatic fashion. I'm going to sleep on it tonight and see what I come up with in the morning.

    My fear is that master cylinder part is scrammed and I'll have to replace that.
     
  20. cegeddin

    cegeddin Junior Member

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    I think the piece on the assembly is damaged. On the right part of the seat there's some scoring that I think would explain the fluid spurting out. Going to call the dealer tomorrow and see if I can get it swapped under warranty.

    This makes more sense to me, I didn't think the threads were an actual sealing mechanism. But with that scoring, it is likely the seat of the brake line can't sit smoothly against the seat on the actuator assembly (or whatever that part is called.) And it isn't a piece I can fix. I suspect the brake line itself could use a little bit of lapping to make sure it is smooth as well, but it doesn't look as horrible when I view it from the perspective of it need to sit against where it does. I have concern that the brake lines being off my experience some corrosion on those surfaces, but hopefully this gets handled quickly.
     

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    #20 cegeddin, Aug 24, 2023
    Last edited: Aug 24, 2023