Brake Pedal Vibration (2011)

Does anyone else feel this on their new trucks?

The best way to describe it is a slight (but noticeable) one second vibration/pulse when the brake pedal is depressed usually 1/4 way down. It doesn't happen all the time (which makes extremely annoying). The truck only has 500kms on it !

I've taken it back to the dealership but of course, they assure me it's 'normal' . There wasn't another 2011 on the lot, but I'm sure the truck I test drove 2 months ago didn't have this. I didn't push the issue with them but it is documented that I raised this concern.

I've spent some time searching online and it seems others have reported the same issue. Some say it's normal (related to ABS), others have indicated the brake booster could be a problem.

Any thoughts?
Thanks,
KN

 

Mine does it too. Im not too worried. I think it has something to do with the different brake system on the newer trucks. Which I also believe is because of the A-TRAC system.

 

It's an AccessCab TRD OR

 

This is a cut and paste from a recent poster on a 4Runner forum who had a similar issue:

"The mechanic drove my car and immediately diagnosed the issue. He told me that the feeling on the brake pedal is the brake motor. Since the neither of the previous 4Runners I've owned have the electronic brake-by-wire system that the new Toyotas have, this feeling is new and foreign to me. Basically, the brake motor powers up depending on the brake pressure being applied to the brake. Adjacent to the brake motor in the engine, is the brake actuator which is filled with an x-amount of brake fluid. When the fluid level in the actuator falls below the pre-programmed threshold in the system, the brake power powers up to refill the actuator to the programmed level.

This explains why the "vibration" isn't felt every time--the actuator is re-filled every time you feel the motor working. But if you repeatedly step on the brake on and off, you will feel the motor power up almost every other press. Or on a long press of the brake, the motor can be felt towards the latter end of the braking because the pressure in the actuator is decreased due to a draining of the fluid and the motor needs to power up to refill.

Apparently this is felt on all of the newer Toyotas (Priuses, Highlanders, Land Cruisers, etc.). The mechanic admitted that he won't be surprised that this will become an issue that will be brought up by the media/Toyota in the future."


Do we buy this explaination? At this stage, I'm just more annoyed (and disappointed) then really concern the brakes are going to fail. I'll just continue to monitor the situation and bring it up again at the first service date and learn to live with it?!

Thanks,
KN

 

Not true. Vacuum is not used in this brake system. Its an electric pump that pumps brake fluid into an accumulator. That fluid is used for braking.

 

Basically what this system consists of is ABS module and brake booster/master cylinder all in one. Known as "Integral ABS" which oddly enough is rather old technology.

I should clarify that the accumulator pressure is only used for power assist. Should you lose the boost pressure you will still have some braking. Just it will be a "hard" pedal feel.

 

my truck seems ok ....but ill check it out

 

I know this is a old thread, But its the only one I have found on this issue.
I recently did new front brakes and SS lines on my 2013 OR. And I bled the brakes and everything was fine. Then I decided it was a good idea to get the brake fluid flushed. So I took it my local Les Schwab and they got it done. Now I have this stupid vibe in the pedal from the Booster motor, or whatever. I have never had it before. Pedal was always smooth. Whats the deal????
If anyone out there knows why it would all of a sudden arise after the Brake fluid flush, please let me know.

My brake fluid is a little over the Max Fill line. But I don't think that matters.
Could it be still air in the system?? Although my pedal feels better than before, not that mushy. I don't know

 

Les Schwab looked over the Brakes again, and checked everything. they purged the system and took out some fluid there was too much in there.
and now its better but still there.

Ive read reports of this vibe/noise on a lot of different models and years with this Brake system that the TRD Off Roads have. So I guess it could be just a normal thing that really shouldn't be "Normal"

 

Any service bulletin on this? My 17' off-road with 100 miles on it does it..seen posts about this issue back to 2011. Many say they have opened claim with Toyota. Toyota denies knowing of the issue. Also was told that's the way they are and it doesn't interfere with reliability