Need advice for notorious Brake Booster issue Toyota refuses to cover

agreed. i just dumped my 2012 because the engine started shuddering at 87k. i just don't know what mfg to turn to for a better experience

 

Any Toyota without the 2ZZ Atkinson engine or possibly the A engine that's in the Camry I just don't fare too well.

 

Order used parts on fleabay and replace booster accumulator and master cylinder

 

Yeah I've seen locally very well removed systems for the generation 3 I've gone and looked at a few because I have the Gen 3 with this problem but I've decided to just phase them out. But I've seen these completely disassembled with the reservoirs the two pieces the connections all of it for like 350 bucks not too bad and the stuff looks brand new down here in the south now in heavy rust areas and what not these components will not look so nice possibly and at 350 versus 12 13 15 whatever hundred it is I would have to probably give it a whirl.

 

i can't believe toyota is stiffing you right at the end of warranty

 

Yes Toyota USA will run you right on over it right quick It's the American way this is how we do business now legally speaking and all of that sort of thing.

 

If you replaced the engine, you can do this job. The tools you may need to buy
will be far less than any labor rate you'll be paying.
You can purchase the Xtools D8 system for about $500. And you'll be able to use
it for other things on your car, and other peoples vehicle. It will walk you through the
bleeding process.

Just take your time, and try not to stress.

 

Here's a good video:

And attached is some info from Toyota, including the replacement procedure, the version that DOESN'T require dropping the lower support frame,

 

No, do not do this. Order brand new from dealer (replace only master cylinder, they are like $700 retail no need to replace pump itself) but match the VIN # to revised part number and dont waste your time with used junk parts. Do it right..

 

Many have turned in their fanboy hats over these issues. For others it is just a matter of time once they reach 150,000 or more.

2010-15 Prii are particularly problematic with engine, brake booster, inverter and the expected battery issues. Gen4 and now gen5 hybrids have benefitted from our problem children.

I would buy a new brake booster. The labor will be the same but used can mean more headaches when it proves to be the wrong part number (too common on eBay) or it fails in the near future. A full brake booster fail will suddenly reduce your braking power and will increase braking distance. The er visit will eat up the couple hundred saved by used parts.

 

Anyone knows what are the signs of ABS Booster main assembly and Pump w. Accumulator failing apart from a trouble code?
I have about 20 seconds pump motor sound every time the driver door gets open and then after vehicle started and I press the brake and hear a good five seconds of pump sound every time I press the brake. Is that normal?
I looked up the pump accumulator pressure sensor voltage on my live stream scanner and it hovers around 3.7V when the pump finished running. Then the voltage starts to slowly but surely drop little by little, but the pump is not running again for a long time. Is that normal or the unit will soon start to fail?
Also I was looking if it is possible to refurbish this assembly instead of buying a brand new part that costs a small fortune, but could not find a refurbished part only used or new...
Installation does not seem to be intimidating, just need a two way scanner with ABS bleed maintenance function once installed and do the bleed. My small thinkdiag BT scanner seems to have that function, did not try that yet though.

 

Not every bidirectional scanner will work. Even with Techstream or one of few that are reported to work many have trouble.

If there are no codes and the brake booster does not run on its own except when entering and after a brake operation you have some life left. 20 seconds is longer than normal but Toyota would not replace without codes.

 

I have the same brand (thinkcar) 2-way scanner as in this video, just a smaller thinkdiag BT version that works with Android cellphone and has the same maintenance ABS bleed function. That's why I think it is not too hard to replace DIY if you have the 2-way scan tool with the bleeding function. I can read every sensor in the car with this tool, but again I did not do such bleeding yet, no need... yet.
It is possible that brake fluid change would extend the life of the unit since it gets more corrosive with time by absorbing moisture, so probably the ABS bleeding is not a bad idea after all. I have only done brake fluid change without bleeding the ABS so far. I have 265k km or 165k miles on the car.

 

A complete bleed has restored function in the past. For one day. Codes?

 

I did not get any codes yet. Checked my little scanner and it appears to have the same ABS service menu as in the video, just on the cellphone screen via BT instead of this tool tablet.
I am now thinking of doing the bleeding the old fluid from ABS booster and accumulator just as a preventive measure.
Is that a good idea or bad, what can go wrong?

 

I just went through this on my 2010: $1200 for parts including tax & shipping (see links in post). For me it was 2 days, one day to pull the old parts out & the next to install & figure out the bleed procedure.
Techstream for newbies after replacing ABS Master Cylinder and Pump Assembly | PriusChat

When it first failed, I could tell the accumulator pump was cycling often so no surprise when it did fail.
I did try a brake bleed which would usually get the accumulator pump cycle time to >10 seconds & satisfy all the computers. The Prius would operate correctly for a short length of time (2-20 minutes) before failing again.
So you can bleed the brakes right now if you would like. Never hurts. Don't loose the very nice bleed screw "covers" on each wheel! They are good quality covers & protect the bleed screws very well.

If you can swap out an engine you can swap these brake parts.
I would suggest taking it _very_ easy removing the brake lines! Be gentle. Don't bend the steel lines. When reinstalling actuator, just start the 4 nuts on the firewall & let the actuator be loose. Use just your fingers to put the first couple turns on the fittings. At this stage you can tilt the accumulator a little to help start each fitting. Once all the fittings are started, use fingers to snug them down as far as possible, then you can tighten the 4 nuts at firewall. Only then you can fully tighten the line fittings. I found good-n-snug worked for me

Everything I did is in the above post. I was not able to get the specific Techstream brake bleed procedure completed, but I found a work around using Techstream.

Prius has ~1K on it after replacing both units & its like "new" again (at least the brakes are).

 

Thanks for sharing kc410, the new parts prices are better than I previously found, feel betternow.

I feel guilty for hijacking this thread with my questions, but I hope this info will help the OP owner, ProblemPrius too.

BTW, in the booster replacement video that I posted above the bleeding was done with Thinkcar brand Thinktool Pro scanner (not Toyota's Techstream) and my little Thinkdiag BT dongle with cellphone app appears to be able to do the same thing as this tool in the video does.
Now I feel better if this unit starts to die I will not wait to get stranded, but will order the new parts and do the replacement.
Thanks again.

 

You appear to have a 2012 so iirc at least the actuator will be a different part number.
Hint: You "can" drive "forever" with a failure such as this.
The Prius will never have any regeneration braking & the brake pads will take much more abuse. Panic stops will not work well
The 2010 was being driven very little & I put off doing this repair for >2 years.
Initially I had ordered just the actuator & had it sitting around for 2 years. I was always kinda worried that just the actuator might not fix the problem. Decided to do the right thing & replace both so I ordered the pump & installed both. Am happy its done!

 

Yes, my 2012 is different part#, but the price is the same on the site you have provided. I live in Canada though and the website does not seem to have an option to ship here. Sent them an email whether they will ship to Canada as they have the best prices I saw so far... fingers crossed.