TSB BR001-07 Brake actuator noise

Hi Phil,

1. What does "fluid is retracting" mean?
2. Did you suck old brake fluid out of the reservoir (and replace with new) before starting the job?
3. How did the Panasonic Toughbook help the brake wheel cylinder bleed process? In other words, if that diagnostic tool was not available, how much more difficult would it have been to bleed the four wheel cylinders?
4. How much fluid did you use in bleeding the four wheels? Wouldn't that process have purged all old fluid out from the master cylinder?

Thanks.

 

1. basically you tell the scantool (ok im going to bleed the rear left wheel now) and as soon as you hit okay you should crack the bleeder. The stream of fluid should shoot out in a nice stream (probably no air) but then it starts getting less and less and that's when you should close the bleeder to prevent air from getting in. I guess the motor/acutator is doing the pump action because the person inside the car is not suppose to pump pump pump like normal cars bleeding procedure.

2. you can use a siringe kinda tool but i think I just added new fluid on top of what i had, i sucked it not too long ago (4 months) so i wasn't too concerned how new the fluid was, plus it was free so i'm not complaining!
3. The tech was in my car operating the panasonic toughbook, he was going through the menus and letting me know when to crack the bleeder (that's when he probably hit ok on the computer). And then from there on i just bleed all four wheels, as he kept inputting the sequence on the computer (he was high in the air so at times i missed my chance to bleed and he had to activate the menu again).

its impossible to bleed without the tool, you can't just pump the brakes because its just a stroke simulator, you can't command the lines to pump the way a traditional system linkage does. Hense the computer does the bleeding for you, you just have to crack the bleeder and be sure to close it when the fluid looks like its shooting less.

4. he filled it beyond the MAX level, by th etime i was don ewith four wheels it was below the MIN level, so i just top it off.

honestly out of practice it made no difference. However i do notice the actuator noise being more vibration like after using the brakes (even when its all regen) when accelerating from a turn or what not. But that sound was there before I bled the brakes, maybe now because of the process the noise got louder? Only apparent at low speeds, braking performance has not been affected.

 

anybody have any success getting this covered out of warranty window?

I have an '07 prius and bought it because i put miles and miles on my car and had to offset some of the environmental guilt. (already at 47k)

any suggestions, thoughts, or ideas are very welcome

 

I'd love to go in and have this taken care of under warranty. But there's no way they'll do it without being able to reproduce the problem. And the problem has only happened at elevation (on my visits to Tahoe or Mt. Shasta). Happens there consistently, and has never happened here at home 50' above sea level. And I know from experience that if they can't reproduce the problem, that they won't fix the problem.

 

I had the "squeak" (my dear wife complained about it first) and went to the dealer (long out of warranty) and asked for a $39 "Brake inspection" mentioning the squeak. They told me I needed a full front brake job (including rotors - since I was well over 100k miles at that time, they said that they were corroded - not true) for $550 (ouch). I asked them a simple question, "since the noise occurs when the car is not in motion, how can the pads/rotors be involved?" and then asked to see the boss. They bled the right front caliper for me and the noise disappeared for no extra charge.

I managed to get the appropriate job done for less than half the normal price because I had done my research (Thanks Priuschat), read the TSB and used my head.

JeffD

ps: I am now over 139k miles, no squeak, and still have the original brakes as the pads still have significant life left - maybe I'll revisit this issue at 200k miles .

 

Hi All,

I have an '08 prius that's making the infamous brake 'chirping' sound. It gets a lot worse w/ cold weather and altitude. I took it to the local Toyota megadealer and showed one of the service managers exactly where the noise was coming from. I think it's what you all are describing as the 'brake actuator' - a small black 'box' between the inverter unit and firewall that has brake lines coming out of it. I can feel this unit vibrate when the chirping sound happens. The folks at the dealer diagnosed it as noise coming from an electrical relay in the brake actuator (I'm not buying it though - it doesn't sound like a relay to me - sounds like a pump that's pumping a mixture of a gas & fluid).

Does anyone know if there's a TSB out there covering this issue for '08 models? Thanks!

 

07 / 08 should be covered in this TSB!!!

http://priuschat.com/forums/toyota-.../29211-tsb-br001-07-brake-actuator-noise.html

 

I have an '07 with the chirp. It happens very occasionally, but it has happened on and off since I got the car new in 2007.

Can anyone tell me if this is something that NEEDS to be fixed, or if this is just a nuisance noise that will do no actual harm?

I'd like it fixed, but I don't think the techs will be able to reproduce the noise on command, and from what I've read I don't think they'll do the fix if they can't reproduce the noise.

 

this problem has been in existence for a long time now.... I have never heard of an actual problem created from the symptom.

My two cars do it occasionally too, but seem to work perfectly.
I have about 80K on both of my 06 cars now.

There is some pretty cool technology that goes into these brakes, ie: brake assist, regen, etc... its easy for some of that technology to bleed over even when the car is stopped.

Nevertheless, it doesn't seem to be an issue other than a bit un-nerving.

 

The first few times I heard it, I thought someone behind me was gently honking at me.

I love the car and can live with this as its one -- and so far only -- quirk... as long as ignoring it doesn't make anything worse.

Thanks for the reply, I feel better about it now.

 

Toyota is aware about it and since its brakes that we are talking about here, it would be a huge liability for toyota to simply ignore it.

I'm certainly not an authority on the subject, but I have been hearing about it for quite a while now "couple of years" and I have never noted anyone who has gotten burned yet.

Many have gotten toyota to give some satisfaction, but it sounds like they did it under protest and for the sake of good relations rather than real fear of liability.

I've never had my brakes act strangely or fail one time.

 

Our 2007 model at 21K just started to 'chirp' about 2 weeks ago. Its a pleasant "noise" - as if the 2007 seems to be communicating!
However, we cannot determine whether its the front or rear brakes.
None of the posts indicate whether this "noise" should be repaired right away. Any comments? Thanks.

 

the post you quoted from galaxee indicates there is no urgency nor even a real need to bother.

 

Thanks to this message board, I saved $2400!

My 2006 Prius developed a chirp/squeak when I pressed the brake pedal during a vacation in Flagstaff. I took my car to Findlay Toyota where they attempted to convince me to replace the brake actuator for $2400. To make a long story short, I found out about TSB BR001-07, and when I told them about it they retracted their recommendations and said that I didn't need to do anything after all- not even brake bleeding..! Please do not get service from that dealership.

I had noticed the chirp after ~2 days in Flagstaff. Perhaps an air bubble was created when we were driving through the hot desert (>110F) and then up to ~7000' elevation. The squeak/chirp went away immediately after we came back down to sea level.

 

has there been any reports of this happening with a 2008? The description is dead on with what i am hearing

 

Is there a TSB for 2008 ? Or 2004-07 should cover it as well?!
The brake noise can be heard after pressing brake pedal a few times while car is stopped/about to stop.
Anyone? Thanks!