1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Hi! I need advice changing the brake actuator on classic prius.

Discussion in 'Generation 1 Prius Discussion' started by Ol drippy, Oct 4, 2021.

  1. Ol drippy

    Ol drippy Junior Member

    Joined:
    Oct 4, 2021
    21
    10
    0
    Location:
    Usa
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    newbi here, but not actually, I’ve been lurking around these forums for years reading about how to do maintenance on my 2003 prius.

    recently my brake actuator went out, as I found out from my break light and ABS light coming on along with the most annoying sound I’ve ever heard. Seriously Toyota, if you’re ever reading this please make the person who approved this high pitch sound sit and listen to it for 10 hours.

    anyway, I’m good at taking things apart, and figuring stuff out, I have bought a replacement part and I’m planning on removing the old one from the bottom of the car.

    I’m guessing Jack stands will be better than ramps because I’ll have to bleed the breaks when I’m done. I also have tech stream and I’ve read that their is a procedure to properly bleed the breaks, at least I’m guessing I have to use tech stream to do this, but I don’t know how and can’t find any forums talking about how I go about this.

    Before I start I need to get a couple bottles of dot 3 break fluid, a flex extension for a socket wrench, and a 10mm open end wrench to remove the break line from the top of the brake actuator module.

    It looks to me like I need to drain and remove the break fluid reservoir, cap off the hoses to keep them from spilling break fluid, unhook the break line from the top, unplug the electric plugs from the top, then remove the mount from the bottom to remove the actuator, followed by putting the new one back in reverse order.

    Any advise going forward would be appreciated, except take it to toyota and pay them as much to fix it as it would cost for a good used car.

    the engine has 150k on it, it’s been treated well, and I’ve gotten 250k out of this exact model car before, so I figure it’s worth my time.
     
  2. Ol drippy

    Ol drippy Junior Member

    Joined:
    Oct 4, 2021
    21
    10
    0
    Location:
    Usa
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    Finally found information on using tech stream to bleed the brakes, I couldn’t find it because my module is bad and not even talking to tech stream.
     
  3. Ol drippy

    Ol drippy Junior Member

    Joined:
    Oct 4, 2021
    21
    10
    0
    Location:
    Usa
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    So I successfully replaced the brake actuator, it can be replaced from underneath but it would help if you knew a couple things first.

    I had to basically figure this out on my own because I couldn’t find any information on it except someone saying they did it from below so they didn’t need to disturb the ac lines.

    you will need 10mm open end wrench
    12 mm open end wrench
    A Jack stand
    mm type socket set
    Phillips screwdriver
    Some straight screw drives might help
    the replacement break actuator unit

    #1 turn the wheels all the way right and pop the hood, after popping the hood I always unhook the 12v battery and remove the orange jumper on the traction battery for safety.

    #2 Jack up the front passenger side of the car and put a Jack stand on the proper part of the frame.

    #3 remove the windshield wiper units, and all of the assembly involved with housing them until you reach the firewall and can easily see the brake actuator.

    #4 remove the bolts holding the stuff on around the break actuator to make it easier to remove. Also, you will not have to remove the break fluid reservoir, but take the bolts out because it makes it easier to get to the brake actuator if you can move the reservoir.

    #5 removing the skirting under the car on the passenger side, when the skirting falls down you’ll see the serpentine belt and pulley system, this is the hole where the break actuator will come out.

    #6 carefully start unhooking the brake actuator, you’ll have to unhook two plugs, one hard break line, the rubber tube from the brake fluid reservoir, I suggest you plug the reservoir or it will leak whenever it’s in a position to, you’ll also have to unhook a hardline with a red coating that runs from one part of the break actuator to another part of the brake actuator, I did the rubber line and the hard red line after removing the mount that holds the break actuator in place, it’s easier because you’ll have a little more room.

    #7 very carefully remove the old break actuator through the hole that we’ve made by the wheel.

    #8 put the new brake actuator in and put it all back together in reverse order.

    Note, the abs break light and annoying sound will not go off until you hook up tech stream and run the break bleed procedure.

    If any of this sounds confusing I would suggest not attempting this procedure, it’s not too hard but it assumes you have a basic understanding of the vehicle’s mechanics.
     
    ammdb likes this.
  4. Ol drippy

    Ol drippy Junior Member

    Joined:
    Oct 4, 2021
    21
    10
    0
    Location:
    Usa
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    One more update to anyone who might come across my posts and use them as insight into changing the brake actuator, it turns out that the car will shut off the high pitched squeal and lights after the car has run for a little bit, but I still recommend using tech stream to bleed the breaks.

    If you’re reading this because you had the same problem, good luck! It can be done.
     
  5. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,448
    3,751
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    I wonder if you cleared the codes after doing the work? The fact they cleared after some drive cycles would suggest you didn't.

    You should always clear existing codes and rescan for new codes after doing work.
     
  6. Ol drippy

    Ol drippy Junior Member

    Joined:
    Oct 4, 2021
    21
    10
    0
    Location:
    Usa
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    I haven’t done that yet, I plan on it in the next day or so.
     
  7. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,073
    14,982
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    From your description, I am thinking you did not replace the brake actuator.

    In a Gen 1, the master cylinder, the actuator, and the pump/accumulator are all separate assemblies. The actuator is more amidships.

    g1brk.png

    It sounds more like you replaced the power supply portion, also sometimes called the accumulator and/or pump.

    Other than which part it was, that seemed like a good complete description that is sure to help the next person who needs to replace ... umm ... that part.
     
  8. Ol drippy

    Ol drippy Junior Member

    Joined:
    Oct 4, 2021
    21
    10
    0
    Location:
    Usa
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    Yeah, that might be! I’ve heard people call the part all sorts of things, so just to clear up any confusion if someone is reading this thread searching for answers here is the full description of the part and its Toyota part number, that way they might find and order the correct part to change.

    01 02 03 Toyota Prius ABS Pump Control Module Anti Lock Actuator 47070-47020 OEM
     
  9. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,073
    14,982
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    It looked like this, right?

    [​IMG]

    There's a thing to watch out for with Toyota part numbers: sometimes parts have engineering numbers marked on them, which are xxxxx-yyyyy just like part catalog numbers, but they're different numbers. You can see this thing has a label on it that says 47070-47020, but that's not the official number for the part, which is 47071-47010. Weird, right?

    When online sellers go to resell the things, often they will list the part under the number they see on the part, to save the trouble of looking up what its real part number is.

    To give the full description of the part and its Toyota part number, it's safest to link to Toyota's listing (even if you then decide to buy a less expensive option elsewhere):


    2003 Toyota Prius Pump sub-assembly, brake booster with accumulator. Brakes, suspension - 4707147010 - Genuine Toyota Part


    You can see that in the description you pasted, the seller just strung together every name they'd ever heard for any part at the front of the brake system, to make sure they'd get the most Google hits no matter which part people are really searching for. For you it worked out, if it ended up being the part you needed, but it's a danger to others, if say they actually need the actuator, or the control module, and Google sucks them into this part because of the keyword spamming.
     
  10. Ol drippy

    Ol drippy Junior Member

    Joined:
    Oct 4, 2021
    21
    10
    0
    Location:
    Usa
    Vehicle:
    2003 Prius
    Model:
    ----USA----
    Yeah, but I bought it pulled from a old prius so it was on the mount as well.
     
    Dave_T likes this.
  11. Dave_T

    Dave_T Junior Member

    Joined:
    Mar 31, 2019
    1
    0
    0
    Location:
    AZ
    Vehicle:
    2002 Prius
    Model:
    Touring
    Thank you and ChapmanF for this post. Do you actually need a tech stream, or can you just turn the to the on position and hold the brake pedal down periodically. I have a Scangauge II, so that could hopefully clear codes, but no tech stream.
     
  12. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,073
    14,982
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    To bleed the brakes completely, you'd better have Techstream.

    Other scan tools that can do the brake bleeding can be options, like some reviewed in this thread for Gen 2:

    Gen2 OBD2 app review | PriusChat

    But Gen 1 had different network details, and far fewer Gen 1s were ever built, and I would be leery of just assuming any tool reviewed for Gen 2 will work for Gen 1, unless someone has specifically tested it.