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Will the car maintain the 12V while in invalid mode?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by SB6, May 22, 2020.

  1. SB6

    SB6 Member

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    Need to use invalid mode, but I also seem to have a weak 12V right now is it safe to put the car in invalid mode with my weak 12V, or should I replace the 12V first? I wanted to take a little time to shop around for the 12V
     
  2. burebista

    burebista Active Member

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    When my mechanic changed my brake fluid I put the car in Invalid mode.
    Changing fluid was a job for 8-10 minutes.
    Voltage drop was 0.1V from 12.6V to 12.5V.

    Of course, before putting in Invalid mode I shutdown AC/ventilation/interior lights/radio.
     
  3. tankyuong

    tankyuong Senior Member

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    Depends on voltage
     
  4. SB6

    SB6 Member

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    2.9V before a jump :oops:
     
  5. ChapmanF

    ChapmanF Senior Member

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    The brake bleeding procedure, especially the longer one that also bleeds the actuator, has a seqience that ends with fully emptying and repumping the accumulator, six times.

    Even on a strong battery, by the time you get to that part of the procedure, the pump may end up sounding like a dying wind-up toy by the fifth or sixth repetition.

    If I had a power supply around that I could keep attached to the battery while going through the procedure, that's what I'd probably do.
     
  6. SB6

    SB6 Member

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    I may need to jump the car to get it to start again. Could I just keep the jumper cable and 2nd car connected throughout the bleed process?

    Also, I was initially just going to do a bleed for one brake, as I think I got air inside, but then decided to do a flush. Didn't know about the actuator bleed. You think I should do that as well? Would you be able to tell me how much fluid that would require?
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    That's hopeless, not "weak".

    What do you need Invalid Mode for? If it's a (relatively discretionary) brake fluid replacement, I would suggest replace the battery first, and get an appropriate charger (smart charger, one will run through a cycle and can be left on indefinitely), and have the charger hooked up when you do the invalid mode procedure.

    For a complete, 4-corner brake fluid replacement, using non-Techstream method, I used 2 pints, Toyota DOT3.
     
  8. SB6

    SB6 Member

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    Yup, I was going to do a brake fluid flush. I wanted to see if I could do the flush before replacing my 12V, as I was still trying to figure out what replacement to buy. I think I've decided on buying one from the dealership now, but they weren't picking up the phone earlier, and are closed now...

    Anyways, I was thinking I could hook up a 2nd car to my battery with jumper cables to act as a "backup" power supply while flushing my brakes in invalid mode. Would that work?

    Does the 2 pints for 4-corners which you mentioned include the actuator bleeding which ChapmanF mentioned?
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    No, just bleeding fluid out of the 4 corners. I followed the Repair Manual non-Techstream method in attached, with copious watching of @NutzAboutBolts. The only exception I took with the video was to follow the Repair Manual sequence. In a nutshell: you start at the front/right corner, then go counterclockwise. Next is front/left, then rear/left, and finally rear/right.

    I basted out as much as practical from the reservoir at the outset, then topped up with fresh. I was careful not to let the reservoir level get crazy low, just in case...

    I had a charger on the battery for the duration. I'd recommend deal with the battery issue first, and for extra safety, get a charger.

    The last time around (done this twice now, 3 years apart) I missed a simple but crucial step, and could not get into Invalid Mode: the parking brake has to be on. Not sure why, but it does. Watch the video carefully, for the steps to get into that mode.

    Read carefully the actions that can kick you out of invalid mode; you don't want to do that. A low battery might be one, not sure. One for sure is turning a wheel. Not sure why. But be careful.

    Steps for me:

    1. Raise the whole car and support on safety stands.*
    2. Remove all 4 wheels.*
    3. Put car iin Invalid Mode. (with charger connected). Check and note (maybe even mark) the level of fluid in the reservoir.
    4. Baste out most of the reservoir fluid, refill with fresh. It'll take about a cup (1/2 of the first pint). (There's a strainer basket inside the reseroir, with just a narrow slit that allows you to reach further down. You want to have some sort of syringe with a very skinny longish spigot on the end. Again, don't go crazy low.)
    5. Commencing with front/right. It's good to have a proper bleed bolt attachment pushed onto your drain hose. It's like a little ball socket: pushes on and locks. I typically break the bleed bolt slightly loose with a socket on ratchet, just for better control. Not enough that it's bleeding, just slightly loose. Push the attachement with hose onto the bolt, run the other end into a largish jar with a hole in the lid. No need to have brake fluid already in the jar I found. Note, @NutzAboutBolts using vacuum suction throughout, I found a simple tube into a jar worked fine.
    6. Have an assistant sit in the driver's seat, pump the brake pedal a couple of times, then push continuously.
    7. With a box wrench, crack open the bleed bolt, for just a split-second, then quickly shut it. With the fronts that's all you can do. Talk with the assistant, they'll be reporting their foot dropped to the floor very fast.
    8. Repeat about 7~8 times, then go to left/front, do the same procedure. By now you should be getting into the second (last) pint.
    9. Go to the left/rear corner and repeat. Except, here you can leave the bleed bolt open till the cows come home. The assistant pushing brake pedal will report it doesn't drop. I would suggest 3~4 somewhat protracted bleeds. Keep in mind you want to do all four, end up with a slight amount in reserve, for possible top up.
    10. Repeat with right/rear. Worth noting: as you go, you regularly need to check fluid level in the reservoir, keep topping it up. You don't want it running dry. Aim to get to the end with a few tablespoons in reserve (just in case you want to fine tune level later), and the level where it was at the outset. I wouldn't save it long term though: if you don't need it I would add it to the drained, for recycling; it doesn't keep well. I think if you brought it to dealership service department they would recycle it for you.
    11 Verify all bleed bolts are snugged up ok, and reinstall the protective caps, wheels back on, lower car, torque wheels. :)


    * You can do the job with the car on the ground, but I think access is a lot easier with the car raised and wheels off.
     
    #9 Mendel Leisk, May 23, 2020
    Last edited: May 24, 2020
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  10. SB6

    SB6 Member

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    So I decided to give it a shot with another car connected with jumper cables. I got to your step 5, but... I can't find the bleeder screw/bolt :oops:. Is it part of the same piece that's the valve? If so, I guess I did find it, but it's not 10mm... Maybe aftermarket?
     
    #10 SB6, May 24, 2020
    Last edited: May 24, 2020
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    The bleed screws are near top of caliper, with black rubber protective caps. A little more than 1/4" dia by maybe 3/8" high. You need 8mm and 10mm box wrenches for them.
     
  12. SB6

    SB6 Member

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    Did you see the pictures I posted in the imgur link? Is that the bleed screw?
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

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    Ahh. Yeah that's the protective cap, you have to twist and pull off. One end is 8mm size, the other 10mm. I forget which is which.
     
  14. SB6

    SB6 Member

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    Are you able to see the other 2 pictures?

    Is it 10mm with the cap on? Cause other than that, I don't think it could've been 10mm. It might be 8mm, I'll try again tomorrow
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    Finally managed to see all 3 pics. I would suggest try to just post directly in the thread btw; it's a pain with Imjur (ok on pc, but a hassle on Phone).

    Yeah those are them. All should have caps, 2 are 10 mm and 2 are 8 mm (wrench size).

    I would use proper bleed valve attachment too. Here's one example, the elbow shaped items:

    Mityvac MVA6913 Brake Bleed Adapter Kit
     
    #15 Mendel Leisk, May 24, 2020
    Last edited: May 24, 2020
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  16. ChapmanF

    ChapmanF Senior Member

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    Makes ECU think car might be in motion.
     
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  17. SB6

    SB6 Member

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    Ahh, thank you so much! I was extremely confused, as I was watching NutzAboutBolts's video, and he does the rears first. I was doing the front first, and didn't realize that he was doing the rears, so I was confused about why his bleeder valve position and size was different from mine. After figuring that out, I was finally able to bleed my brakes without too much issue. Also finally replaced my 12V! :)

    These definitely would've helped a lot. I picked up a cheap kit from AutoZone, as I wanted to finish the job ASAP. However, the kit I bought, OEMTOOLS One Man Brake Bleeder Kit, wasn't great. It includes 2 pieces of tapered attachments. The larger side you stick in your hose/tube, and the smaller side you stick in the bleeder valve. Maybe I did it wrong, but it would've really helped if I had an attachment that went over the valve. This attachment kept coming out of the valve.

    Have you used this exact kit? If you were happy with it, I might order it for whenever I need to do another brake bleed/flush. I wonder if I can return the kit I bought... I really wasn't happy with it lol. It was just $10 though, so whatever.

    For anyone that's curious, I flushed my brakes using the ECB Invalid Mode, without using Techstream.

    I used a sort of siphon method. I stuck one end of my tube as far into the little channel on the side of the inside of the brake fluid reservoir. I placed my collection container at a lower height than the reservoir. Then I first took a small syringe and stuck the end inside my tube (at the end not in the reservoir). I pulled the plunger until I had a stream of brake fluid through my tube into the plunger. Then I pinched off the end of my tube, remove my plunger, and stuck the pinched off end of the tube in my collection container, keeping it at a lower height than the reservoir. Then I unpinched the end of the tube and waited for the reservoir to empty. I wasn't able to get it fully empty -- I'm not sure if you're supposed to be able to do so. But I got it as empty as I could using this method.

    I did end up replacing my battery with a fresh battery, before doing my flush. For anyone that's curious, I think I could've completed the flush even with the dead battery, as long as I had another (running/on) car hooked up to the dead 12V using jumper cables.

    With the fresh battery, I had the car in invalid mode for at least 20 minutes without any backup power source/charger connected, and the car seemed to be fine. If I had access to a charger, I definitely would put it on just to be safe, though.

    One of the things that cancels ECB Invalid Mode is the car not being in a 0 km/h or 0 mph state. Like ChapmanF mentioned, I guess turning the wheel makes the car think it's in motion, so it cancels ECB Invalid Mode. The excerpt from manual you attached earlier specifically mentions "Do not rotate the brake disc while ECB (Electronically Controlled Brake system) Invalid Mode is
    selected.
    "
     
    #17 SB6, May 26, 2020
    Last edited: May 26, 2020
  18. Davee

    Davee New Member

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    Hi Mendel, is it safe to set the car in invalid mode with the charger connected to the 12 battery? what I leant from my charger use instructions is never to swtich on the car power before disconnecting the charger. Another silly question is after comleting the rear brakes bleeding, can I switch off the car and do front brakes flush by depressing the brake pedal manually?