Brake Accumulator failure C1391

I have the same problem ((

 

call toyota for goodwill repair help. if no go, look around for a mech who can install a salvage unit.

 

Thanks, will try.

 

Update 6.18.18 - Toyota dealership refused to help and repair for free or even for reduced price. So I went to used market (website:car-part) in this web database have contacted MD sellers. Have bought online booster and actuator pump assembly, but when arrived for pick-up I found, that seller prepared for me just actuator pump without booster part. Disappointed but got a full refund by seller. After that situation I was sending photo example of parts just for double-checking if they realy sell whole unit of ABS system. Finaly have got used part for just $200 dismantled from 2013 prius with 56 000 mil. Took it to lockal mechanic shop and was pre-estimated around $300 for replacement work. Will come back with updates how it feels after replacement.

 

Hello everyone,
After one week driving my 2010 Prius with replacment parts, I am satisfied with the results. Break's work perfectly, I can hear the actuator noise just rarely (when damaged it was every 5 to 10 second). The only obstacle was to reset on the 2010 Prius traction, breaks and ABS lights on dashboard. As well as the replacement parts were from 2013 Prius, mechanic had to update software. Asked extra $60. In. Conclusion: I spent around a month and $572 on the used parts an labor for replacement all inclusive.
Hope to have no major problem with my 2010 "Goldy" in the future. ))

 

I have this issue also, was your final labor around 350 bucks or 4-5 hours? After the software programming did all the warning lights turn off? When all your error lights came on did you lose the regen braking where it felt like you had to brake much harder to stop the car?

 

Hey Zurab, we had similar problems, except I did not have VCS light on. Jkan and I had the exact same problem I think, at least from his description on his thread. C1391 I believe was the same code that came up for me too. The solution for my 2010 Prius was a Master Cylinder replacement (however they also replaced the brake actuator but did not fix the issue). I had the guys over at HybridPit in Buena Park figure this out for me. Good luck!!!

 

Yes, my mechanic initially asked $300 for labor, but cause of programing problems additionally paid $60. And yes break needed deeper pushing.

 

After resetting prgram

Yes after reprogramming all lights are gone.

 

Can you share which part # you replaced for the master? On the Gen 3 is the accumulator and master cyl one single part? How much did you pay for labor (how much labor time)?

Thanks!

 

The always-tricky bit with the Prius brake system is that these two words accumulator and actuator are both names of parts of the system, and they seem so similar and easy to mix up, but it's worth about four figures in cash to you to be careful not to mix them up.

In a Gen 3, the actuator and master cylinder are one single part. The accumulator is separate. (And not all gens divvy them up the same way.)

-Chap

 

Chap, thanks for the clarification. Which is the part that usually fails and needs to be replaced, is it the actuator/master or the accumulator? Which one is more $$$?

 

They're both expensive, the actuator/master-cylinder more so. (It's actually more than just those two things, it has an ECU built in also.)

The accumulator assembly is less money, though still a chunk of change. And it's a labor nightmare to replace, just because of cramped access. The original method in the repair manual would have you disassembling the front suspension to get to it. When it later turned out they had a batch of bad ones and needed a recall, they actually designed and fabricated special tools just for getting that sucker out and back in without suspension work. If you can find the PDF of that service campaign (T-CP-D0H-A510-D), it will give you good ideas. You won't be able to get their custom-fabbed tools, but the pictures are good enough to get the gist.

That same PDF will also show you how to check for the (long shot, but worth checking) chance that you have one of the bad ones and are owed the recall. (You can tell be which way the label is stuck on.)

As for which of those two assemblies your problem is, that's hard to say. They both can develop problems. The Repair Manual and the New Car Features manual describe them well enough (and Techstream gives you a lot of access to the internal sensor readings and controls) that you could have a go at determining which one is at fault in your case.

-Chap

 

Can anyone provide the part numbers for each? I to am in the same boat. 2010 Prius with ABS, brake, and Traction light on. C1391 code. Dealership says $4000, Toyota would cover half, but I’m reaching out to the owners of the dealer to see if they will provide a loyal customer assistance. If not, I plan to find the parts on the market, and have my local buddy’s shop do the install if possible. Also, do the part numbers differ, as I’d like to figure out the model year part number that doesn’t have the same issue. Is that 2012+?

 

If you buy an accumulator from a third party source, check the label orientation to make sure you're not getting one that should have been removed from the supply stream.

From the reality-check department: the ones in the bad batch were recalled because they would wear out extra fast. That probably doesn't mean that the ones from good batches are somehow immortal and will never ever wear out.

-Chap

 

Do you have a picture or description of which ones to avoid i.e. are the labels different colors, are there different part numbers on the faulty batch vs the re-designed part etc?

 

That link that's provided, click on it for your answer

 

Whoops sorry, time for another cup of coffee. Thanks for sharing the link and ChapmanF for posting it originally! If my label is facing the wrong way does that mean I'm eligible for a free replacement under the recall? My VIN didn't show it was eligible when I plugged it into to the toyota.com recall lookup.


I bled all my brakes last night with a Snapon Solus Ultra which walked me through the steps and performed all the abs actuations and stroke simulations.

The only part I couldn't figure out is where the bleed valve was on the actuator or master cylinder so I skipped that step. There was a lot of air in the rear right corner (first one I did) where I opened the valve no fluid came out for about 3-4 seconds followed by a rush of fluid shooting out. I'm hoping I just had a lot of air in the system which made the pump work overtime to compress the fluid.

The brakes feel much firmer and grab much faster now but I still hear some pump noises at a stop with my foot on the brake pedal. Going to drive it for a few days and see if the codes return.

 

I suppose this is a good place to post my experience with a faulty brake actuator. Thanks goes to user "homeyclown" AKA "borgestes" for helping me BIGTIME over PM. Thanks man!!!

I have a 2011 Prius III with about 65K miles. This problem began when I noticed a frequent pump/buzz noise a few months ago. The noise sounded familiar, but much more frequent - every 10-15 seconds. I looked into what it might be, and discovered that it was likely the brake actuator module. I brought the car to the dealer to confirm and they found that there were no codes being thrown, but they also heard the noise. After I suggested that it was the brake actuator, they said "maybe" and quoted $4,500 to repair. What a joke! They said just keep driving it if I want because there were no codes.

After much advice from @HomeyClown AKA @borgestes on this forum, I decided to try fixing this myself. I perform basic maintenance on my cars myself, but have never done any brake work.

I purchased a used brake actuator (read the above explanation by @ChapmanF for the distinct names for related parts). I could find the existing part number by carefully looking in the engine bay with a flashlight. I purchased a removed unit with the same part number from a wrecked car. As explained elsewhere, the "brake actuator" actually performs multiple functions, and includes a computer component. By purchasing the same part number, I did not need to reprogram the unit like @Zurab Laliashvili did. In hindsight, it could be advantageous to purchase a newer version of this part and reprogram it, in the event there was improvements made to this part.

After purchasing the above part and necessary tools (line wrenches are essential - not regular wrenches!), I waited until I had time to get to the swap. During this time the pump noise began to be much more frequent (3-5 seconds) and the brake feel was horrible with obvious pulsating. I could also hear a hiss in between pump noises which I'm guessing was brake fluid leaking past a valve in the brake actuator. Then, last weekend, the dashboard lit up like a christmas tree and I lost normal breaking function. I still had brakes, but had to mash the pedal way down, and braking was not smooth at all. Also, regen braking totally quit.

I immediately got to work on the replacement. I first removed a few parts in the engine bay to give access to the brake actuator: the wipers, wiper motor, a cover, and a metal tray were all removed. Then I removed the lines from the existing actuator. Then I removed the actuator from the brake pedal and removed the 4 nuts holding it to the interior firewall. I pulled the actuator from the engine bay and placed the new one inside in reverse order. The final step was to flush the brake system. I chose to use the Techstream software for this, although it is also possible to do without Techstream (both explained elsewhere on the forum). I already had this software and cable from when I first bought my car and needed to program a new key.

Techstream has an option for brake bleeding after replacing the actuator. This process is a bit more involved and does some sort of checks/tests as well as a "linear valve offset relearn" procedure. This procedure apparently restores correct brake feel after bleeding the brake system. I think using techstream for the bleeding is preferable because of the additional checks/tests and relearn procedure. I also used Techstream to clear the codes that had lit up my dash the day earlier.

The work seems to have been a total success. Brakes feel totally smooth. No lights on dash. The pump sound is back to normal and operates when the driver-side door opens, and occasionally while driving/braking.

Overall, this took me most of 2 days to do. I am an amateur when it comes to this kind of work, so I expect it would only take an afternoon for more experienced folks. But the key point is that if you are the least bit handy, this job is 100% doable as long as you have the tools and patience to learn. DON'T PAY THE DEALER! I can't believe they would seriously quote me $4,500 for a repair on a relatively new car worth approximately double that. This cost me $110 for the used part and $20 in brake fluid. I also bought a few tools, but I don't count those in the cost of the repair because I'll use them for other things.

Even if you don't want to fix this yourself, you should at least purchase a used brake actuator and bring it to a mechanic. This will be only 4-5 hours of labour and cost you around $500, as mentioned earlier in this thread.