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Constant beeping sound and dashboard lights after stopping in the middle of doing rear brake.

Discussion in 'Gen 2 Prius Main Forum' started by Roll Eyes, Feb 19, 2023.

  1. Roll Eyes

    Roll Eyes Junior Member

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    Hello all:

    I was trying to do rear brakes on my 2005 Prius, which has over 227,000 miles on it. I did the front brakes with a great success a couple of months ago. Recently, when I was driving on highway, three wheel studs and the lug nuts attached to them on the rear passenger side broke, so I had to open the rear brake to install the wheel studs. When I opened the brakes (i.e., the drum or circular iron lid), I noticed the adjuster screw (the thing that we move up and down with a screw driver) to expand and contract the break shoes was slightly bent and one of the springs was off the hook and was hanging. I also noticed oil leak to the wheel cylinder, which I will replace.

    It has gotten dark and I couldn't complete the brake job. I want to do my own research and complete the brake job when I find time. I have to admit that I have many questions that I need to find answers to. I do not want to invest a lot of money in this Prius and do not want to take it to a dealership. This is my first time doing rear drum brake job on any car. I am not sure if I can do my own research and complete the rear brake job myself.

    Here are the issues. The circular iron lid will not close and the adjuster will not move down and so the brake shoes will not move in or contract to enable me to close the iron lid. So, I put the tire back on the Prius without closing the lid. I am not driving the vehicle until all the issues with Prius are fixed.

    When I turned on the engine, the following lights in the picture showed up on the dashboard and a constant beeping sound when the engine is on, as you can hear in the below video.

    Will the constant beeping sound and the lights will go away after I finish the rear brake job, which I plan to do in the next couple of weeks? Or is it going to be a major problem that will continue to give me a headache?

    Any advice or input is appreciated. Thank you in advance for your time and help.

    IMG_20230219_203513.jpg

    IMG_20230219_180311.jpg

     
    #1 Roll Eyes, Feb 19, 2023
    Last edited: Feb 19, 2023
  2. TMR-JWAP

    TMR-JWAP Senior Member

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    looks to me like the system pressurized itself and you blew the piston(s) out of the brake cylinder.
    The brake shoes have been pushed apart more than they are designed to be pushed apart, which is probably why you couldn't get the drum back on.

    Did you kill all power to the brake system and bleed off the accumulator prior to working on them?
     
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  3. Roll Eyes

    Roll Eyes Junior Member

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    Yeah, whatever it is, I figured the drum brake wheel cylinder is a toast and I need to replace it. I have bought a new drum brake wheel cylinder and did the research on how to replace it. I think I will be able to replace it with a new drum brake wheel cylinder. I will also bleed the brake fluid and air bubbles afterwards, before driving the car.

    Yes, I figured that, as well. I was not able to push the adjuster downwards with a screw driver, and consequently the brake shoes will not move in or contract, to put the drum back on.

    No, I did not do that. However, I left the keys away from the car, before starting the rear brake job, which was what the youtube uploaders suggested me to do.

    Is there a fix? Will the constant beeping sound and dashlights go away after I finish the brake job? I am planning to disassemble the entire rear brake system and put all the parts and springs back together. I know it will take a lot of time.

    Thank you for your reply.
     
    #3 Roll Eyes, Feb 19, 2023
    Last edited: Feb 19, 2023
  4. Roll Eyes

    Roll Eyes Junior Member

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    If anyone is wondering what that loud engine noise is, in addition to the constant beeping sound, in the posted video. I will need to replace the Oxygen Sensor (O2S), a fifty dollar job, and the loud noise will go away.

    This Prius is giving me a lot of issues. I owned a 1999 Corolla before for 20 years and it never gave me any issues, other than oil changes and tire changes and rotations. I loved that Corolla, as it was a rock solid car, and I could trust it to take me to a city 3000 miles away.
     
    #4 Roll Eyes, Feb 19, 2023
    Last edited: Feb 19, 2023
  5. ChapmanF

    ChapmanF Senior Member

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    To complete the bleed procedure (which you'll need to do), you should have either Toyota Techstream on a Windows laptop, or one of the alternative tools able to do the brake bleed sequence—some of the offerings reviewed in this thread will do it:

    Gen2 OBD2 app review | PriusChat
     
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  6. Ernie stires

    Ernie stires Member

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    I just replaced a rear cylinder with pretty much the same issue the piston had hyper extended. Replaced the cylinder, used brake cleen on the other parts and buttoned it up. In then bled the brakes, it’s a kittie different than other vehicles, but overall pretty much the same. I used a 1 man bleeding kit with the hose going into a catch bottle and bled out about 1/2 pint. Afterwards I cleared the code, I think I had to use Techstream, but they cleared and I’m good to go. I did not use Techstream to do the bleed process but I guess I could have.

     
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  7. ChapmanF

    ChapmanF Senior Member

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    Any ideas on what caused the three wheel studs to break and the mangling of the internal brake parts?

    That would have taken a fair bit of energy.

    I suppose if a shoe return spring had been incompletely hooked to begin with, and came loose, and a shoe pivoted loose against the drum at speed ....

    If it were me, I'd want a pretty good idea what the story was before buttoning it all back up.
     
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  8. Roll Eyes

    Roll Eyes Junior Member

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    I have driven cars for about 20 years, and never once had a personal experience of a wheel stud breaking while driving, on any of the cars I owned or drove. This is the first time happening to me. I am thinking of two reasons (1) the wheel studs had probably gotten old and rusted and became weak to snap off, or (2) the guy that rotated my tires screwed the lug nuts to the wheel studs too tight. Can't think of anything else.

    Same feelings with the spring in the rear brakes coming off loose and hanging and the adjuster (star like screw) becoming bent, when I opened the drum; the car is probably too old. Again, I drove a trustworthy Corolla that was more than 20 years old, which was a solid car and ran like almost a new car with hardly any problems. This 18-year old Prius is giving me problems after problems. When I try to fix one problem, it gives me another problem, and weird sounds from the car and weird messages on the dashboard, that I don't even understand. I am thinking if this Prius is even worth keeping and worth my time it is taking to fix the problems that are compounding one after the other.
     
  9. Roll Eyes

    Roll Eyes Junior Member

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    Good job. No need to use techstream to bleed the brakes. Bleeding brake fluid is a simple process. While the engine is off, loosen the bleeder valve, you can even put any container (don't even need a hose and catch bottle, but having a bottle helps to see the air bubble, I guess), push the brake for a minute or two (sometimes, even 30 seconds is enough), and let the brake fluid fall into the container, and tighten the bleeder valve after you finish this process.

    Thank you for the replies, people, as always.
     
  10. TMR-JWAP

    TMR-JWAP Senior Member

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    Perhaps this is part of the problem. You think your Prius is just like all the other cars you've owned. It's not. You can fix anything by hitting it hard enough with a hammer. You can do jobs halfassed like tom, thinking it's all good. BUT, eventually, it will bite you with this car.
     
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  11. ChapmanF

    ChapmanF Senior Member

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    It is in a car with a conventional brake system. It is easy to get into trouble assuming it also is in a Prius.

    Assuming you are only bleeding a rear line and no air is anywhere else in the system, successful bleeding can sometimes happen without a scan tool, doing the operation with the brake system awake and a steady pressure on the pedal, as longtime PriusChat member hobbit described here (scrolling down to "Brake fluid"). The system's own pump and accumulator will supply the pressure, so pumping the pedal isn't needed. But depending on the amount of fluid bled out, the system may react as if detecting a leak, and valve off that line.

    A front line, if there is no air anywhere else, can be done by pumping the pedal with the brake system powered down.

    But if there's a possibility of air being in the underhood brake components, there isn't any procedure without a scan tool that's sure to get it all out.
     
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  12. Roll Eyes

    Roll Eyes Junior Member

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    Can you? I can't. I never said I can.
     
  13. Roll Eyes

    Roll Eyes Junior Member

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    What city in Indiana do you live in? Do you fix Priuses or cars, even as a hobby, to help friends and/or family members?