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ABS Actuator replaced - Scantool + Pump Error

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by PriusDummy, Aug 14, 2023.

  1. PriusDummy

    PriusDummy New Member

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    2008 prius that was showing signs of ABS actuator going bad. Got new one from toyota dealership and swapped it, done except for the brake bleeding procedure which I'm having some unexpected issues on at the moment.

    Car starts fine, communicates with techstream (via a Mongoose-Plus dongle) drama-free with no new errors, just the ABS codes.

    Forewarning I'm not very mechanically inclined.

    Issues:
    (1) When starting the brake bleeding procedure on techstream for an ABS actuator replacement like instructed in the repair manual, I get to the first screen that says to turn IG off, remove the 2 ABS-MTR relays, and turn on again, and it errors out asking if I'd like to try again. The same error screen did suggest the 12v battery was low but I couldn't tell if that was the default error output or actually telling me something. Either way I have the 12v charging on a 3A charger currently. Made sure to do a 'Health Check' in the beginning as well (recommended in another thread). Also tried restarting my laptop and unplugging/replugging the dongle. Was wondering if there were any other recommendations outside the 12v battery.

    (2) Brake pedal goes to floor. I'm not very mechanically inclined so maybe thats expected but it's offputting that I've refilled the brake fluid reservoir to the top and the brakes bottom out completely with zero resistance. Is that expected given no bleeding has been done?

    (3) After I finished installing the actuator and everything else, I jumped the gun and pressed the brake pedal before I had refilled the reservoir. The pump worked (to my delight) and I thought nothing else of it, but a day later when I'm trying to bleed it doesn't sound like it turns on at all. I'm worried I sucked in a bunch of air into the actuator and screwed something up. Do I just need to get the techstream bleeding process to work to fix this? Or do I need to consider the walk of shame to the dealership?

    Appreciate any advice at all, I learned a lot about my prius during this process.
     
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  2. Tombukt2

    Tombukt2 Senior Member

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    You did suck a bunch of air into the stroke portion on the firewall That's what you're pumping when you pump the brakes with the relays out so now you've got to get the stroke portion to fill up with fluid from the reservoir again which apparently you sucked your pump dry almost by pumping the brakes with the reservoir empty etc etc when you did this if you would have used block off clamps on the reservoir's three outputs You could have saved yourself a bunch of hubbub. So now you've got to fill the reservoir and if you trace the hose the fat hoses that go from the reservoir all the way over to the stroke portion of the system which is like the master cylinder of a regular car what I did was take the relays out Make sure the reservoir is full Make sure the feed that's going over to the stroke portion of the system actually has brake fluid coming out of that hose and trying to get into the stroke portion on the firewall then all I did was open the furthest bleed screw from the driver seat in the front which would be the right side and lay there on my towel and watch the fitting that I have cracked open with my wrench in a few minutes brake fluid will start to drip out of that zerk fitting that your wrench is on that's cracked open drip drip drip drip right down onto the bottom edge of the inside of your wheel and tire drip drip you can put a towel there if it makes you happy drip drip drip five or six minutes of dripage until you can see a half of a width of the line that indicates the full and low marks when you see movement of about a quarter inch in the reservoir things are starting to happen close that zerk and go over to the left front and crack it and wait for the drip drip drip to start it will start burn one do something it's coming then it starts to drip drip drip give it a minute more or wait till you see movement in the reservoir drip drip drip yeah I know it's boring. Close that zerk now that should pretty much have the front ready to start the bleed procedure but if you must you can go in the house and get your son or your wife and get them to pump up the brake go back to the right side have them pump the brakes 10 15 20 times like it says in the manual and hold down on the pedal now you crack the zerk you see a straight stream of fluid it starts to slow down like when you're taking a leak and you close that zerk before you get to dribble have them pump it up one more time repeat that procedure on the same fitting You see no air pushing noise nothing straight stream it starts to get weak clothes dessert do the left same way see what the drips did they let they just forced the air out by the dripping without anybody having the pump but we're pumping anyway just to make sure we see what we see. Now I believe your next step is to put the relays in if I remember correctly and you'd be pushing next next and then you'll be doing the thing where you're pumping the brakes 30 times and 30 seconds while the line is moving across the screen and it's activating the valves internally of the new actuator and then after that you're going to bleed the rears similar to the fronts You really don't need a whole lot of bunch of pumping going on but if that makes you feel better let them pump up hold down you crack the zerk thing is when you crack the fitting back there the fluid is going to come straight out under pump pressure so don't be in front of it it will squirt you right in the chest.
     
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  3. PriusDummy

    PriusDummy New Member

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    @Tombukt2 I'd like you to know many drip drip drips were had and it worked! I could tell large pockets of air were forced out of the system from the front brakes being pumped by a second person. I jacked up just the passenger side of the car and put it on a jackstand for easier access to the front bleed valves and that alone made fluid in the reservoir drop noticeably.

    I successfully got thru the techstream ABS bleeding procedure. Brakes now feel firm and good, and can't press to the floor. All the lights on the dashboard still light up EXCEPT for the traction control light. The 'READY' light actually comes on. The ridiculous infinite "beeeep" sound that was made the moment the door was opened no longer sounds.

    My techstream issue came from me just not knowing anything I guess. The system says to set the parking brake in the very beginning, which I thought meant to have the car literally set to "P" for setting the transmission or however it works, while the bottom left foot-pedal was just an emergency/back-up brake, but I guess they consider it the parking brake. I also connected a 3A battery charger to the 12v during the entire procedure and pre-bled things to help it along like you instructed, but the techstream goes thru the same thing anyway and I'm not sure either of those were needed at all.

    I can't keep going tonight but progress was made and I'm grateful for the help. Next steps are to bleed the engine coolant system including the heater core/pump, reset the DTCs, and perform some testing.

    Also, I might go thru the ABS bleeding again (assuming it's okay to put the pump thru multiple bleeding procedures). I'm considering this because the bleeding went smoothly except when the pump was supposed to run while holding the brake pedal down for the RL and RR, for some reason the pump just...didn't go for those. We double checked the instructions and it looked like we were doing it right. Tried multiple times and decided to just move on and complete the procedure.
     
  4. TMR-JWAP

    TMR-JWAP Senior Member

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    As a side note, the Repair Manual has a list of steps to perform PRIOR to replacing the brake actuator. It also, as expected, has all the steps to perform after replacing the brake actuator. Never hurts to read instructions for a critical job like this. It can't possibly hurt more than reading one of Tom's posts....:LOL:
     
    #4 TMR-JWAP, Aug 16, 2023
    Last edited: Aug 16, 2023
  5. ChapmanF

    ChapmanF Senior Member

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    In the + column: punctuation and paragraph breaks (and pictures!). In the − column: sometimes iffy Japanese-to-English translation.
     
  6. PriusDummy

    PriusDummy New Member

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    Fair enough. I did try to follow them as closely as I could but it seemed like at every major point I'd hit a snag that forced me to improvise. I'd be done with this by now if it went as smoothly as the manual makes it out to be, or the youtube videos.

    I tried to access the techinfo site since I didn't save a copy of the actuator replacement section and I think its down? Says im unauthorized, thanks toyota. Wanted to double check if I missed a step in there.

    I have 2 questions now (for anyone to answer if they could).

    The actuator runs A LOT less than I'm used to. I think that's expected if the old one was going out and running more often to compensate, but the new one doesn't run when I open the door or when I tap the brake pedal and press the start button. I have heard it kick on occionally and for very short periods, ss that healthy actuator behavior? I wouldn't know, its my first prius and I bought it used 8 months ago. I reset the DTCs and nothing has popped up yet on techstream except the one AC code that everyone says to ignore.

    Also, I put the car into dianostic mode to bleed the engine coolant, ran the engine continuously with the radiator cap off and filled, and opened the radiator bleeder valve by several turns but no fluid came out whatsoever, not even a drop, 100% dry. Heat was turned on inside and I revved the engine a few times, and let it sit for quite awhile. Is that a good indicator of air in the system still?
     
  7. dolj

    dolj Senior Member

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    If you mean at all, then that might be a problem. You might have to press the brake pedal 6 to 8 times to lose enough pressure to make the pump run. As for the door opening, that could take all night, if not longer, with a good brake system.
    Maybe, maybe not. Did you try squeezing the hose coming from the engine to the top of the radiator?

    And, to clarify, the bleed valve you're talking about is the one at the top left (US driver's side) of the radiator? Maybe it is blocked?
     
    #7 dolj, Aug 17, 2023
    Last edited: Aug 17, 2023
  8. PriusDummy

    PriusDummy New Member

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    @dolj That seems to line up with the replacment's behavior then. This morning I opened the door and heard 1-2 very distinct clicking sounds, sounded like it was coming from the driver-side large relay box (maybe the ABS-MTR relays), and maybe the pump ran for an instant then stopped which was kind of concerning. But when I pumped the pedal 4 times it came on strong and stayed on while the pedal was down, stopped when the pedal came up. Might just have to do some real testing to know for sure. No lights have come back on yet, so that's good.

    I did squeeze that hose, the large one that goes into the radiator right below the bleeder valve and gets hot when the engine is running, but I'll try again and use my muscles and make grunting sounds next time and see how that goes. And yes, the bleeder valve that's opened with a 6mm hex thing is the one i used. Is there a way to check if it's blocked or to unblock it?
     
  9. Tombukt2

    Tombukt2 Senior Member

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    You squeeze all the hoses starting as low as you can like your milking a cow squeeze the hell out of them like you're trying to hurt the cow's teat. With the reservoir full and the radiator known to be full. Then go around and milk all those hoses good and fast fast as you can open and close your hand then pop the radiator cap off and see if the level's gone down any put some more in do it again maybe three or four times it's only takes about 18 minutes and then take the car out for a drive good fashion get on a state road where you can maintain 55 for a few minutes and 95° weather it's going to take a good 20 minutes for the car to get the full operating temperature in the design of this type of Prius and it may never get as hot as your Corolla or gas car that just pulled into the driveway. You'll only see that kind of heat after you're coming in from a 2-hour trip from somewhere and even then most of the Prius under hood is touchable where is the regular car not so much.
     
  10. ChapmanF

    ChapmanF Senior Member

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    The pump only runs as needed to keep the accumulator pressure within spec. The tighter the system, the less the pump has to run. So when it runs quickly and stops, that makes you happy. When it has to run longer, that's when you're concerned.

    If your pump ever has to stay on the whole time the pedal is down, you've got a big, big problem. I'll assume what happened here is just that you happened to hold the pedal down for about the same length of time the pump ran.
     
  11. PriusDummy

    PriusDummy New Member

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    [​IMG] You're right chapman, that was just a coincidence. Went at it multiple times, pump brakes 4-5 times before it kicks on and when held down it runs for ~4 seconds then turns off. Brakes are looking good.

    Sorry for the barrage of questions. Brake bleeder just needed to be looser I guess I kept opening it until coolant (and some bubble) shot out. When I turned off the engine from maintenance mode I heard a sound that kinda sounds like its maybe a coolant leak somewhere right around the engine but I never really messed with any of the hoses there during the job. Maybe someone could confirm? Coolant got up to ~200F.

    Attached video link /w audio. Camera was just me getting close to the sound. it almost sounds mechanical
     
  12. PriusDummy

    PriusDummy New Member

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  13. Tombukt2

    Tombukt2 Senior Member

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    Cannot hear a thing
     
  14. PriusDummy

    PriusDummy New Member

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    For me the volume toggle is on the top right for mobile, bottom right for desktop
     
  15. alftoy

    alftoy Senior Member

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  16. Tombukt2

    Tombukt2 Senior Member

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    On my fancy Google Pixel phone when I hit the button to unmute the speaker on this app for this sound of this Prius It has some up and down arrows and then the page changes No worries it's not that important.
     
  17. Tombukt2

    Tombukt2 Senior Member

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    Got it by enlarging the screen and very carefully touching the speaker anyway that sounds like a dry sucking pump or something along those lines not the belt of the water pump or anything like that on the front of the motor It doesn't seem like it sounds like an electric pump that's not pulling liquid if you will.
     
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  18. TMR-JWAP

    TMR-JWAP Senior Member

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    Either your engine water pump bearings are failing (most likely) or the idler pulley bearings. Been there.....bought a killer 2008 in Myrtle Beach a few years ago that had pretty much the same exact sounds, but had no leakage from the weep hole or other visible leakage. Coolant level was fine. Bought the car, drove straight to Auto Zone and bought 2 gallon jugs of coolant. I threw 'em into the back of the car and drove straight to Columbia. Ended up having zero problems on the drive, even though it sounded scary as heck, and installed new pump, idler and belt (since I was already in it) that weekend and all noises were gone. .
     
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  19. PriusDummy

    PriusDummy New Member

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    @alftoy ty so much! saved

    I did my first official test today driving around, accelerating hard and slow, braking hard and slow, ran the AC and heat on full blast, so on so forth. The braking is sooo much smoother and I could be making it up but the regen feels a lot more prominent. Actuator runs way less, but still kicks on strong, 100% sure on that. No codes so far.

    My research (i.e. google) last night also pointed towards the water pump for the weird sound but the symptom didn't reappear during the test. I'll listen for it during a long highway drive tonight and probably just replace it anyway as a preventative maintenance item, but that's a next month problem for now.

    I appreciate the insights ya'll shared. Helped me save a 08' /w 275k miles, on to live another day.
     
  20. Tombukt2

    Tombukt2 Senior Member

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    That car should go to 600K if an accident or rust doesn't take it out easily actually