Help: Issue when I hit a bump and have foot on brake

I've had my 2008 Dbl Cab TRD off road taco with 52,000 miles for a month now. It has me kind of worried though. When I go over a bump (i.e.speed bump or pot hole) at a decent speed like 20 mph and have my foot on the brake, I hear a noise that sounds like the engine revs or like a vibrating sound on the outside of the car. Additionally it feels like the car wants to keep with its momentum even though my foot is on the brake consistently. I know its not the engine revving more since I'm watching the tachometer, thats just the best way to describe the sound.

Anybody experienced this or know the cause...when I first bought my truck I had a Certified Toyota dealership inspect it since i bought it from car max. The only thing they told me is that it was about time to replace all my drivetrain fluids.

 

Have you replaced the fluids? Do you have a video or audio clip so we can hear what you are hearing?

 

ABS kicking in maybe?

Edit: from what I understand alot of people complain about the ABS kicking in too easy. Alot of people have said when they hit a bump they notice it. Its normal if thats what it is.

 

Ummmmm.....ABS?

 

Sorry I don't have a video or noise clip yet. I can try to get one some time soon. I haven't replaced the fluids yet. Honestly, I talked to a guy at work about the fluids and he'd heard from a different Toyota Dealership that at 50k miles the fluids should be fine and not replaced yet. Does it sound like a problem with ABS or something normal? My last Taco didn't have ABS and was the only other car I owned.

 

Sounds like the ABS to me to.
Mine does it as well. There is a thread on here about disabling the ABS if it bothers you that much.

Shawn

 

Oh yes.
OP is it somewhat of a grinding noise?

 

It is normal, if it is the ABS. Is it almost like a ticking sound at a rapid rate?

Edit: LOL john was faster than me.

 

Its the ABS and its normal. When you have your foot on brake and when you go over a bump/pothole your tires end up not going the same speed and it thinks a wheel is slipping
(one is slowing down and the other isnt) when your trying to stop.

 

Thank you all for the fast responses. It sounds like thats the issue and its normal. Appreciate it greatly.