I have a 2005 SR 4R with 45K miles. Just tonight I noticed that there is a buzzing, vibrating sensation when I brake. It ALSO happens when the car is parked. It's every 3rd brake depression.

At first I thought I had dropped my cell phone (vibration mode) down by the brakes..but no...but that's EXACTLTY what it feels and sounds like. A quick, momentary cell phone vibration sound/feel coming from the brake pedal on every 3rd depression.

It is not the brakes, rotors. It is an audible vibration that is also felt through the brake pedal.

Would any of you 4R pro's here have any info on this? Is it covered under warranty? Is it a recall repair? I'm planning to take it in to the dealer tomorrow.

Could be an acting up anti-lock brake system.

That is weird though.

It sounds like it might be your vacuum pump... our 4Runners have an electric pump to help keep full vacuum in the brake booster.

Your 4 runner had a 3yr/36k basic warranty. You are over on both. You had 5 years on powertrain and that is over as well so no to that as well.

As mentioned it sounds booster related.

Actually I still have 8 month warranty left as I bought is TCV (Toyota Certified Vehicle).

Anyhoos..the service rep. called me back and said that it's "normal" and that the brake is charging up (as you guys just said). Thing is that it didn't start happening until yesterday (I've had it about 4 months now). I bought it with 41K miles and it's at 44K.

He said I probably didn't notice it before..but no..I noticed it immediately last night. I have to say it doesn't sound or feel right still..even though he says it is "normal".

This electronic vibrating thing (like you cell phone in vibration mode) was happening every 3rd time the brake was depressed, but the dealer service rep. said they were able to make the brake do this every time while it was there this morning.

I mentioned to look at the Master Cylinder (as I read somewhere here taht that was the culprit), but he said that it was the brake charging..still.

..why all of a sudden would it be doing this "virbrating" thing if it was "normal"..

So Doozi, is this normal for the electric buzzing/vibrating sound/feel coming through the pedal..or is there a problem with the brake booster?

How long have you had the vehicle? Did you just start noticing it?

If it has changed recently, then maybe you've got a bum electric booster, but I'm guessing that it's fine. Mine seemed odd when I first got it, but it has become normal to me... it reminds me of one of those little aquarium pumps and I guess that I do feel a slight vibration in the pedal. It actually startled me the other day when I was working under the dash trying to locate a keyed-hot in the fuse block... had the key on (not running) and when my head was under there, it went off.

I'm thinking either the Anti-lock has an issue or your rotors are warped, which would explain the slight vibrations when braking, but not at a complete stop. I had issues with warped rotors in my 3rd gen.

Do you feel that vibration if your foot's on the brake pedal while you're stopped and it happens? That would rule out the "warped rotor" idea... highly unlikely to be warped rotors with that few miles... depending on circumstances, of course.

It is normal. It is the brake booster pump.

Not sure if this sound is normal.

I just started hearing this same buzz, and I absolutely have not heard it before. Now it buzzes at every third brake depression, even with engine off, key in ignition. If it's normal booster operation, why is just now making noise? Thanks for any input!

08 Sport V8, 40k.

I think it's normal electric brake booster behavior.
My brake makes that vibration/noise every third or so depression.
I also didn't notice it after a few weeks of owning my 4R. It was snowy morning, when I first noticed it, when ambient is very quiet. Once your senses are tuned in to the sound and vibration, then you start to notice it more easily.

Might have to trade it off...ridiculous

Read the thread. I am currently in the process of having this problem repaired. Recieved the entire unit this afternoon and will be having it installed within a week. Originally I was told the unit was 3,000 dollars. Not sure where the shop got that quote but if you click on the links you can find it new for about 1,700 dollars. I found a used one that comes with a guarantee for 600 bucks. How often are you noticing the pump come on? I noticed about a month ago that I would hear it about every 30 seconds. Then two weeks ago it started coming on every 10 seconds and it is drawing some amps cause my lights dim when it kicks on. Good luck.

I've had my 2005 for about 2 years, and it's been doing the same thing as the OP described for about 1.5 years (vibrating every 3rd pedal depression or so). The lights dim ever so slightly once and a while when it happens. It still stops fine, so I haven't been too motivated to drop the $$ on a new hydraboost unit.

zonianbrat: keep us posted on whether or not you are able to fix the issue.

I will keep you posted. It better fix the problem after as much $ as I am having to drop. I wouldnt mind living with it if I knew it was going to just stay this way. But I am noticing the pump is getting louder and I timed it to every 7 seconds regardless of brake pedal pumps. I have kids so I want to know everything with the brakes and ABS are working correctly.