Finished replacing booster/accumulator. Brake Bleed Next

So I just replaced the booster and accumulator in my 2012 Prius, following youtube videos. I got my emptied brake fluid reservoir reinstalled and I'm about ready to start the bleed.

First question I have for you, is should I be okay with any DOT3 or DOT4 brake fluid or is it really important to stick with the Toyota brand name brake fluid?

For the next step, I am planning on using the authentic (from their website) Tactrix Openport 2.0 that I purchased a few months ago for this job, which I believe is compatible with Toyota Techstream. Unfortunately I think I need to pay like $79 for a 2 day license for Techstream, unless someone has a recommendation for a different software that I could keep for life. I kind of resent having to pay $79 for a 2 day license, especially if things go wrong and I end up having to do this multiple times. I have the brake warning lights, ABS, etc. on on the dash for my 2008 Gen 2 Prius too after someone changed the brakes on it when I was out of the country. I am guessing I need to use the scan tool for that car too when I'm done with this Gen 3 section. I'm hoping I can manage to get both cars done during the same 2 day window.

My understanding is that using the software it will walk me through the steps for the brake bleed and the linear offset. I've never done a brake bleed before but after searching online, people seem to say that the Motive Products Power Bleeder is a great way to do one man brake bleeding. I'd rather not try and round up friends and want to make things easy on myself. So I'm thinking about trying to use that, or is there some reason why I actually need to be in the car pushing the brakes during the software walkthrough bleed process because of Prius being special here?



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As for the process of changing out the booster and the accumulator, Youtube was great. I found like 3 different videos and needed them all to get different perspectives on how to put in and take out the parts, plus searched random forums.

It was mostly okay but I got tied up for a long time getting the nuts back on the rubbery bushings. The ones that look like little rubber 8 shot revolver cylinders. Ultimately I had to lift the wire harness above them up, giving me only a fraction of an inch more to work with, and also found out that the 10mm nuts are tapered on one side before the threads to make them easier to thread on. Undoing the bolt on the wiring harness only lets you move it slightly along the shaft slot but it makes a big difference.

I lost the nuts down into the engine compartment and couldn't find them so bought some 10mm flange nuts that didn't have the taper which were nearly impossible to engage.

I later found the original flange nuts with the taper and it made all the difference. Sticking them on with the box end of a wrench with a ratchet built in was also very helpful. Also, I didn't have flare nut wrenches and so I struggled with getting the brake lines back on at the end. Applying a strong normal force with the open ended wrench by pushing them like 45 degrees into the flare nut was necessary to get them to thread and not back out.

 

That's a great thought on the 12V Battery. Car has set unused most of the last 3 months so battery charge is suspicious.

 

Okay, so I don't have a battery tender but I filled my brake fluid reservoir and tried turning the car on.

My plan was to just let it idle for a while so the hybrid battery would charge the 12V

So far brake lights are solid on just with battery connected. Car seems to start, but the center screen is rebooting itself and even with the car off I am getting a lot of noise from the newly installed brake actuator system.

Also the ICE is not kicking on as I would expect it to.

I found a tutorial video on youtube for installing techstream in virtualbox since it isn't compatible apparently with my operating system.

I got techstream to recognize my tactrix openport but I haven't yet tried to run the brake bleed operation with it or connect it to the car.

Not sure if I need to manually adjust the actuator/sensor first to make sure it doesn't think the brake pedal is constantly depressed or if that will be something fixed in Techstream.

Car battery is unplugged again while I just investigate for a while my next step

 

It appears that it will let me do the techstream brake bleed.



Techstream ECB says to do ECB-R first? ECB shows actuator replacement, but ECB-R only shows fluid replacement. The other options are greyed out. When I select it, it appears to begin to begin the bleed process.


However, I guess this is the sensor for the brake pedal being disengaged (stoplight). With the brake in a neutral position and the sensor extended out as far as possible by rotating the black box with the plug in it and pulling the other thing up, the white thing doesn't come close to hitting the metal thing above it.



So I guess in order to disengage the brake I need to adjust the push rod / yoke thing here.



I'm guessing that if I tried to run techstream prior to this adjustment, it might have some kind of issue because when it tells me to depress or lift the brake it will just see the brake is fully depressed all the time.

 

Hmm, well I can confirm that the old gasket came off with the old actuator

The one I took out was indeed activating the switch properly. However, online it seems that the box under the switch is green for other people and black for me, so it seems that maybe someone has already replaced this component, or there is color variation in the manufacturing.

Everything seems snugged to me



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I adjusted the push rod as far as it can go, and it still isn't close. I think maybe the stoplight bracket or the part that pushes the button got bent somehow. Operation Bending Sheetmetal commencing, I guess. Followed by drilling and adding a bolt to the button pusher if that doesn't give me enough movement.

 

I unfortunately didn't really measure things before I put the new one in.

I completed "Operation Bending Sheetmetal" and now the brake light works properly.



I guess I'll hope for the best during the next step, and hopefully my replacement actuator isn't problematic. I think it was refurbished.

 

Car needed a boost from a jumper battery to start up properly. Now that brake is disengaged, engine also started. I'm going to let it run for a while to hopefully rejuvenate the 12V battery a bit before I proceed with the bleed.

 

So, I attempted brake bleed.​

I originally wanted to make this a 1 person job, so I had this Motive Products 0090 NPT Power Bleeder and a Power Probe BA10 Small Adapter for Toyota. (Plus a few fittings from the hardware store)




I went to start the bleed process, and increased the brake fluid reservoir to 15 psi with this tool. This caused Techstream to report a brake fluid pressure fault. Also, I think I forgot to Clear Memory first in Techstream might have been the real problem, but Techstream was telling me that I didn't make sure the car was in the correct state (ON but Engine OFF, reservoir cap OFF, etc.) and I figured it had to do with the pressure being 15 PSI, so I depressurized. Then I got Techstream communication errors



and finally I did Clear Memory first and then did the Bleed and it progressed on. So, when it gets to the point asking to depress the brakes, I hooked the BA10 back on the brake reservoir and tried to pump it up to 15 PSI. Sadly, the BA10 started spurting brake fluid out the side when I hit 12 PSI and it blew the black lever off and into the engine compartment. I found the lever, tried again, and the same thing happened. So, not sure what's up with that. The BA10 seemed like a highly recommended part, but it seems like it's not getting a good seal... although it did the first time. Maybe it can't seal because it's too slick with brake fluid? I digress....


So, anyways, I enlisted help to push the brake pedal for me. Tried to bleed the brake on the Rear Right which it said was first. Using a 10mm wrench I loosened it but nothing was coming out, I loosened it more and a little fluid dripped when the bleeder valve almost came out. Pressing the brake did nothing though, no fluid flow. I progressed to the Front Left brake and used an 8mm wrench (weird how its different size for each bleeder?), and with a lot of back and forth on the brake pedal some very bubbly fluid came out, but it seemed like less and less and then I could get no more. The fluid never stopped being bubbly.

Okay, so here's my thoughts... You guys mentioned a good battery and a battery tender. I think that's the issue. When I first jump the car to start it and while the engine runs it has a very high pitch noise coming from the intermittent brake accumulator noise. When I put the car in accessory mode it quickly becomes lower and lower pitch.

So I think maybe I am just not getting enough pressure to bleed the brakes, because like you guys said, I need a good charged battery.

So, I guess at this junction, I need to get a new 12V battery for the Prius, and also get a battery maintainer device like you guys suggested. It seems like this is a pretty intense drain on the battery for something that needs to be done in the Accessory mode.

An alternate thought is that I could try and replace my BA10 which apparently is on the fritz, and then maybe it doesn't need pressure from the system but can use the pressure from the motive products bleeder. However, I think the car battery is probably bad anyways, and maybe the Prius is not intended to be bled this way. Maybe BA10 is only for like a Corolla or something.

I wonder if I could have even damaged something pressurizing the reservoir to ~17 PSI?

 

Looks like I need a S46B24R AGM battery. A discussion here revealed people had better luck with the toyota brand battery ( Battery 12V #00544-21171-325 | Autoparts.toyota.com ). Price is similar to others although I might have to drive like 3 hours to get it... might be worth it.

Any thoughts on good battery tender/maintainer/smart charger systems?

 

I ordered a Noco Genius 10. I am trying to charge and recondition my 12V battery with it and then when I try the bleed next time I will leave it attached.

It is a 10 amp charger so hopefully that helps a bit when running on accessory mode.

Not sure I can do much more than 10A without throwing a breaker.