Overboosted Brakes?

[Dubert]

Overboosted Breaks?

I was just reading this SUV comparison on car and driver and at the bottom of the article they said that the breaks felt overboosted. What in the world does that mean?

I think the breaks are awesome for a vehicle this size. The only thing I notice is that when I'm slowing down adding medium pressure to the pedal, it feels like the ABS is going to work pretty hard. It feels like I'm pumping the break pedal lightly, when in fact I'm just holding it steady. Maybe thats what they mean by 'overboosted'.

Anyone else have this problem?

here's the article. Car&Driver 4Runner article

 

[toto]

The brake booster does its job when you press the brake pedal faster than usual, especially if the vehicle is moving faster. If you suddenly hit the brake because some jerk cut you off on the expressway, you'll notice it immediately - the truck will nose dive, and I swear it would stop on a dime, even at 55 MPH.

While it's reassuring that a truck this big and this heavy will stop very quickly if necessary, it does take a little bit of time to get used to driving it. If you're in the habit of stomping on the brake pedal, this truck will break that habit!

 

[sharp4runr]

Haha, the infamous C&D article. You can read more about it, unless your hood scoop is blocking your vision:

http://www.toyota-4runner.org/showthread.php?threadid=9251&highlight=car+driver

http://toyota-4runner.org/showthread.php?s=&threadid=11687&highlight=c&d

I like the brakes on the 4Runner. It has better brakes than my Celica! Maybe they didn't like them compared to the more mushy brakes in the other vehicles they tested, but I like the more sporty feel of the 4Runner brakes. Panic stops are a no brainer in this truck.

 

[mtnc]

If I ever run into the back of another vehicle, I'm going to try the "couldn't see for the hood scoop" defense. Hell, it's right there in black and white in C&D!! Think it will hold up in court?

 

[Barefoot]

Re: Overboosted Breaks?

It feels like I'm pumping the break pedal lightly, when in fact I'm just holding it steady.

Your rotors are probably warped

 

[Dubert]

Thanks for all the replies. That makes sense. I always felt like if I pressed the brake a little hard it would stop on a dime as if I was stomping on it.

how can I tell if my rotors are warped? I'm pretty sure I'm going to have to get my brakes checked out soon anyway. At over 50K I'm starting to hear a little squeal at low speeds and light braking. As simple as they are I'm not too good with brakes and don't know much about them.

Thanks for the input.

 

[rook]

how can I tell if my rotors are warped? I'm pretty sure I'm going to have to get my brakes checked out soon anyway. At over 50K I'm starting to hear a little squeal at low speeds and light braking. As simple as they are I'm not too good with brakes and don't know much about them.

The only thing I notice is that when I'm slowing down adding medium pressure to the pedal, it feels like the ABS is going to work pretty hard. It feels like I'm pumping the break pedal lightly, when in fact I'm just holding it steady. Maybe thats what they mean by 'overboosted'.

If your rotors are warped, you will feel a pulsation when you hit the brakes. It may send a steady vibration up through the steering wheel or even cause the wheel to shake.

Overboosted brakes usually applies to the amount of assist provided by the brake system to augment your pedal effort. For example, if just a little pressure is applied to the pedal and it results in the brakes being grabby they are overboosted.

The other scenario is the brake assist feature designed to apply the brakes faster and harder than the driver can in a panic stop. It uses the high pressure provided by the abs system to squeeze the pads. You will notice a little different feel in the pedal when it is activated in addition to the neck snapping stopping power.

 

[Dubert]

hmm...i see. that makes a lot of sense then. i always felt that the brakes had some kind of assisting. is there any way to make it less sensitive. sometimes i forget they do that and i'll end up coming to a complete stop 20-30 ft before i wanted to. hahaha not really...but you know what i mean. you can definitely feel it when braking when it starts braking harder for you and you have to let up on the brake so you don't stop in the middle of the street.

 

[sharp4runr]

As far as I know, the brake assist is not adjustible even by the dealership. Even if they could, they probably wouldn't out of liability. If they would adjust it, what would stop you from suing them later if you rear end someone?

 

[Dubert]

you make a good point. oh well. if i hit rear end someone i'll just say my hood scoop was blocking my vision!

 

[Casper]

the brake assist controller is a bit over zealous under quick stops but hell, i have race pads and stainless lines on mine ...but under an OEM level, the brakes are good.