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Just changed brakes, now they are sticking. HELP!!!!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by laser411, Sep 25, 2017.

  1. laser411

    laser411 Junior Member

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    You misunderstand, it's the 12v accessory battery that is bad. My traction battery is perfectly fine still, thank god.
     
  2. 05PreeUs

    05PreeUs Senior Member

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    Oh I would not suggest that at all....... Get TWO quality rebuilt calipers and install them AFTER you flush the system, then perform the brake bleeding procedure.
     
  3. ChapmanF

    ChapmanF Senior Member

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    Buying rebuilt calipers is an option, especially if you can find them from Toyota (try the normal caliper part number with -84 added on the end). Toyota's remanufacturing standards are high, so that's a way to know you're getting a quality rebuilt caliper.

    If you get a rebuilt caliper from any other source, beware. Be sure to do a careful piston-return test on the bench, so you catch the ones that have zero return straight out of the box before you go to the trouble of installing them and finding your problem isn't fixed (and possibly misdirecting your follow-on efforts, on account of thinking you just replaced the calipers so the problem must be something else). Also understand that the components used by the 3rd-party rebuilder will be different from Toyota ones, which may preclude any chance of rebuilding them in the future using Toyota rubber kits.

    Also that when you turn in your original calipers as cores to the 3rd-party rebuilder, that'll be two possible Toyota-quality rebuildable calipers taken out of that stream and consigned to being reincarnated as cheapo remans for the rest of their astral existence.

    The bad news is, Toyota's own remanufacturing program (the -84 suffix part numbers) only has spotty coverage of their parts catalog, and I'm not seeing that they have '08 calipers available that way at the moment.

    -Chap

    p.s. I can't judge for you whether rebuilding would be in your comfort zone. It's not especially difficult, you can find (besides the manual, which should be your first reference) plenty of additional helpful information on the net, it keeps your original Toyota-quality calipers on your car (assuming they haven't suffered some kind of irreparable damage), and a cheap extra rubber kit takes very little space to just have around for any future issue with your brakes. That can be a lot more convenient than the usual multi-step process (take car apart, find a caliper problem, get friend to drive you to parts store because car is apart, bring replacement caliper home, put car together).

    Either way you go (caliper replacement or rebuild your own), you will have to open the hydraulic system, and you will have to bleed it afterward. Those may be the most out-of-comfort-zone bits, and they come with either approach.
     
    #63 ChapmanF, Oct 4, 2017
    Last edited: Oct 4, 2017
  4. exstudent

    exstudent Senior Member

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    Try looking up youtube videos of "brake caliper rebuild," to give you an idea of what work will likely be required. The overall process might be the same for most cars, generally speaking. But, as you found out from your attempted front disc pad replacement, a simple procedure that is applicable for most cars, may not necessarily be applicable for the Prius. Always reference the factory service manual, to know exactly will be required.

    Should the caliper piston be rusted, pitted, or both, a new OEM piston would be required, $15.87. 2007 Toyota Prius Parts - Camelback Toyota Parts - Genuine OEM Parts - Free Shipping
    But, if this is the case, a quality remanufactured caliper would probably be best. I would stick with a genuine Toyota remanufactured caliper b/c of fitment issues and superior quality. You get what you pay for. Unfortunately, there seems to be NO Toyota Prius remanufactured calipers available at this time. New OEM caliper is $256.53. There are used calipers available from auto dismantlers.

    Hopefully you'll begin to reference the factory service manual before attempting repairs, to make sure nothing is done incorrectly, causing you unnecessary grief.
     
    #64 exstudent, Oct 4, 2017
    Last edited: Oct 4, 2017
  5. jessiejosco

    jessiejosco Member

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    Are those a picture of your "new" brake pads? One of them looks like it has a deep wear groove in it already. Are you sure your rotors don't have a big lip on them?
     
  6. laser411

    laser411 Junior Member

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    Those are indeed the new pads and there is a small lip on the outer edge of the rotors but it's small and should be outside of contact area (hence why there is a small ridge in the first place).

    I have a hard time believing that I need new calipers as they were 100% perfect before I screwed with them. The piston seal sounds like it might be it but I still can't imagine both of them going out at the same time, right after a pad change.

    I have rebuilt engines before so I can't imagine rebuilding a caliper would be out of the realm of possibility and seeing as money is extremely tight right now I think I will go with new seals and a flush and hope to god it works. If anyone has the procedure from the service manual for flush/bleeding and could share that info, It would be much appreciated. I will tackle this over the weekend.
     
  7. jessiejosco

    jessiejosco Member

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    I agree with you. The brakes were working before you changed the pads. That's why I don't think flushing will help you. I also looked at my owners manual. Brake fluid change is not listed, and from Google, Toyota does not have a recommended change interval for brake fluid.
    From the look of your pads they are contacting the ridges on your rotors on the inner and the outer edges. From my experience, new pads almost never ride in the same place as the old pads. I don,t know if this uneven contact would cause your issues but it is the only problem I see. Rotors are pretty cheap. I have Raybestos rotors on mine and I think they were 32 bucks Canadian each so you can probably get them for 20 in the US. Also your new pads look pretty messed up.

    Also if you can push the Pistons back in easily, I don't see how there can be residual pressure in the hydraulic system and the fluid return solenoid must be open and not blocked with crud.
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Toyota Canada has started spec'ing a brake fluid change. This is from page 25 of the Canadian 2014 Owner's Manual Supplement (outlines maintenance and warranty info), not sure if it's the first year:

    upload_2017-10-6_9-57-13.png
     

    Attached Files:

  9. laser411

    laser411 Junior Member

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    Based on the glazing on the pads, I'm rather sure the wear ridge is not what is causing the friction. The fluid in the reservoir is actually kind cloudy and nasty looking, so I am definitely going to do a flush. I am also probably going to sand down the glazed parts of the pad as I am cheap but I do think I'm going to buy new rotors now. Can I get the rubber seal for the piston at my local dealer?
     
  10. exstudent

    exstudent Senior Member

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    Manufacture's maintenance schedule lists minimum requirements, to give the appearance of low maintenance/ownership costs. You can always hold your vehicle to a higher/better maintenance standard.

    Explain this oddity for a 2007 Toyota Highlander Hybrid vs 2007 Lexus Rx 400h:
    • Cars are pretty much identical in every aspect (engine, transaxle, brakes, radiator, AC, etc); only difference is name badge (Toyota vs Lexus) and price tag (Lexus$$$$$$$ > Toyota$$).
    • The Lexus Rx 400h specifies a brake fluid flush every 30,000miles/36months.
    • Toyota Highlander Hybrid lists NOTHING.
    • Why the discrepancy? Maybe Lexus owners are on average wealthier than Toyota owners. Consequently, Lexus owners might be less likely to complain about the cost of a brake fluid flush?
    • Brake fluid absorbs moisture over time. Its really good to get changed regularly.
    FACT: No lubricant lasts forever, especially when in use.
    Automatic Transmission Fluid is a specially formulated lubricant for transmissions (transaxle for the Prius).
    The only maintenance for the ATF in the transaxle is check and top-off if necessary, per Toyota. NO Drain/Fill!
    You would not take this approach with your engine oil, would you? Of course not.

    Toyota lists the ATF-WS in the transaxle as a "lifetime," fluid. Toyota's idea of "lifetime," is vastly different than most consumers.

    Bob Wilson and Professor Denenberg conducted a transaxle fluid analysis, at specific intervals. They came to a starkly different conclusion than Toyota. READ their study and become enlightened. Transaxle oil, recent analysis | PriusChat

    Read post #473, to see some compelling pictures.

    If you have not been changing your transaxle fluid with some regularity, you should start.​

    Read Art's Automotive perspective on changing coolant, ATF-WS, and brake fluid.
    Art's Automotive
     
    #70 exstudent, Oct 7, 2017
    Last edited: Oct 7, 2017
  11. ChapmanF

    ChapmanF Senior Member

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    Good observation!

    I've yet to see that in a Prius. Ewww.

    You can definitely order it (I linked you to the part number back in post 47); I can't predict whether your local dealer will have it on the shelf or not. Their technicians work on an unforgiving clock where it may be faster for them to throw on new calipers at $300 a side (and get you to pay for them) than to have a $21 kit on hand (that actually requires them to take something apart and put it back together).

    The kit will include the piston seals (one kit is enough everythings to do left and right calipers both) and the other rubber bits (piston and slide pin outer boots and cap for the bleeder screw), the metal rings to hold the piston boots in place, and the gaskets for where the brake line attaches to the caliper, plus a little wodge of the correct red grease for the rubber parts.

    My advice (worth what you pay for it!) would be to do things in steps, taking measurements. If you just change a bunch of things at once and then try driving the car, there are only two outcomes possible: (a) it isn't fixed, and you don't know why, or (b) it does seem fixed, and you don't know why (or how long to trust it). Plus that leaves one of those annoying mystery endings for the rest of us following along at home.

    In particular, if you rebuild the calipers, I'd recommend taking them off the car to a nice accessible work area (remember, you get new gaskets for reattaching the brake line anyway as part of the kit), and start by measuring the piston return (if anything, just to confirm that they really have none, as you were finding with them on the car.) Then rebuild them, and measure the return again, getting actual measurements. What I was seeing with fresh Toyota-reman calipers was a little over 0.3 mm, or about 12 thousandths of an inch.

    If you don't see that on the bench after rebuilding, no point putting them back on the car for a test drive before finding out why.

    Cost difference between buying new cheapo rotors or machining the ones you have is probably about a wash, while machining would be less money than OEM rotors. Matter of preference. If you get new, 3rd-party rotors, you might want to at least make sure they have the same small M8 threaded holes at the hub; those can prove to be a very useful feature down the road if they get stuck on the hubs.

    -Chap
     
  12. laser411

    laser411 Junior Member

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    Quick update, haven't had time to do the flush. I am, however, going to start with that.

    As for measuring the return on a bench, how do I do that when it's disconnected from the car?
     
  13. ChapmanF

    ChapmanF Senior Member

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    Puffs of air into the port in the caliper where the brake hose would attach. A bike tire pump should be fine, you don't want any more force than it takes to slip the piston gently out to tap your block, then release the pressure and see it return.

    This is a better test than on the car and testing with the brake system, because the system is powerful enough to compress your block and stretch your caliper by larger amounts than the return effect you are trying to measure.

    -Chap
     
    Mendel Leisk likes this.
  14. laser411

    laser411 Junior Member

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    Ok, so I have taken the caliper off and verified there is basically no return. I have rebuilt the caliper and now it is much hard to push the piston back. I am convinced that seal was indeed bad. now I have put the caliper back on, I cannot seem to start the bleed process with techstream, just says failed. I do not have the service manual and I have already gone past my budget this month, can someone post the proper procedure with techstream? please and thank you.

    Here is what I did

    -removed abs motor relays (abs mtr 1 & 2)
    -put the car into on (not ready)
    - selected air bleed, usual bleed, FL only, and hit next

    It immediately fails and does not do anything

    Thank you in advance for your help
     
  15. valde3

    valde3 Senior Member

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    You can bleed fronts with relays removed using tradition method. Rears are bled with relays in place using techstream and selecting bleed and just keeping the pedal pressed and opening the bleeder.
     
  16. laser411

    laser411 Junior Member

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    but why is the procedure failing in techstream
     
  17. valde3

    valde3 Senior Member

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    I don’t know I just bled removed the relays bled front’s normally installed the relays and bled rears with techstream. Maybe just try it that way?
     
  18. laser411

    laser411 Junior Member

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    Unfortunately, I do not have a second person to help me hold the breaks while I open and close the bleeder screw. I tried to do it by myself but the brakes are still spongy. One thing to note, ever since I owned this car, when I was in the "diagnostics" screen (Headlight and info button trick) it always said brake off (assuming this is parking brake). The dash light for the parking brake lights up but the brake option in the drag screen never changes to yes. Could this be why my techstream bleed process is failing?
     
  19. valde3

    valde3 Senior Member

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    You can use some one person methods for front brakes. Like just a hose that goes into a bottle filled with brake fluid.

    For rear you can just use something that pushes the pedal down as the pedal doesn’t go down when fluid goes out of the bleeder.

    I haven’t checked that data on MFD. Do your brake light’s work?
     
  20. laser411

    laser411 Junior Member

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    Yes brake lights work and parking brake light works. But neither the brakes or parking brake trigger the brake value in the MFD