I have a 2010 4runner limited edition. There is a road I have traveled a few times and my brakes have given out on me at times in the same spot. I would be traveling down a slight hill with my foot applied to the brake coming to a stop at a stop sign. Right before the stop sign there is a bump in the road. If my foot is on the brake and my car goes over the bump my brake pedal goes to the floor and the car is not stopping and then I guess it is a brake assistance that kicks in it kinda makes a rumbling noise and comes to a stop. It has really scared me not knowing if I was just going to keep going into traffic. It hadn't happened any other times so I just stopped taking that road. However it happened to me the other day I was on flat pavement breaking with traffic when my car hit a bump in the road and the same thing happened again. I thought I was going to run right in to the person in front of me. I take it in to Toyota service center today, and hopefully it will be corrected.

The rumbling noise you describe sounds like ABS.

If you hit a large bump while under heavy breaking, your wheels may loose traction, and the car thinks you are skidding because your wheels are turning slower than your forward movement. It applies the ABS so that the car can regain braking traction.

Maybe but the bumps I have hit in my opinion are small as in I didn't even see them when I hit them just felt it, and the brakes are being applied in a slowing down pressure not sudden or hard breaking. Giving this information do you still think that is what it is?

also when the rumbling happens there is a beeping that goes off

I have noticed the same thing. Happened on my Matrix and on the T4R. I have written it off as ABS kicking in.

Beeping happens when the VSC system engages. There is no audio alert for the ABS system.

Happens to mine every now and then on the road. Hitting a large pothole or bump coming to a stop while applying the brake, same scenario as stated, pedal pressure disappears then the VSC or ABS kicks in. Happens quite frequently off road as well. For the amount of times it has happened, I'm still not used to it LOL.

I don't think it's normal, never had that on my T4R or other venicles. I guess I would be scared enough to drive right to dealership if my brake pedal goes to floor on me. I might expect this sort of behaviour if brake assistance kicks in, but then truck is supposed to stop at once. I'm wondering what delearship mechanic will say about this.

Brake pedal going to the floor while braking, for whatever reason, is NOT a good thing. I would assume the brakes come back fairly quickly as none of the posters here has alleged an accident because of this. Please let us know what the stealership says. I can't imagine the system was designed to do this.

This sounds like the problem that the Prius faced right after the whole gas pedal fiasco. I don't remember too much about it except that the brakes could go out after hitting a bump or pot hole. It was recalled for the Prius, so maybe this is something similar. Definitely needs to be checked out. I however have not experienced this on my '10 SR5.

Correct.

Everything you described is normal except the pedal going to the floor. That is just plain wrong I believe. As others have said, it's the ABS and yes, it's scary when it kicks in. Kind of gives the opposite feeling of stopping, which is counterintuitive, but it's just trying to keep you from locking up the tires and skidding.

There is a spot on a road near me where it's happened in my T4R Trail, my FJ, and my Subaru WRX. You think I'd be used to it by now, but I'm not.

This happens when the car drives "you"...

Everything is, in some form, electronically controlled on these new vehicles. There's no linkage for the gas pedals anymore, all controlled "by wire", the brakes are controlled by the ABS electronics...etc...

The response was....... We think it was caused by your floor mat! Shocker! I feel like that is the response for everything these days. My floor mat was in my old CRV for 4 yrs never a problem and now has been in my 4runner for a year. I am willing to bet my life that what i have experienced was not due to my floor mat, but hey they are the experts so I will leave it out and wait for it to happen again and take it back to them once again. Also, i thought places use to test drive ur car to see if it happened while they drove it? according to my miles till empty they drove it 2 miles which tells me it never left the parking lot!