Brake Pedal Vibrates

[mosi]

Hi there all...

I own an IQ 1.0L VVT-i 5 M/T.

I've noticed that when at the same time I apply brakes on a bumby road, the brake pedal vibrates and I hear a strange noise.

It feels also that the brake application is not good.

It happens only when simultaneously I apply brakes on a bumpy road.

Does anybody know what exactly this brake behavior is?

Is it normal or there is something wrong that I should check?

Thank you guys...

[LA-LA]

Isn't it the ABS vibration?

[mosi]

Hmmmmmm

It might be, but ABS vibration I believe feels different though.

Even if it's the ABS is weird to get activated so easily in a bumby road....

[dash]

Very likely to activate on a bumpy road because the wheels' contact pressure with the ground is reduced as you leave the crest of each bump. When you apply the brakes under these conditions it is similar to being on ice i.e. little resistance between the wheel and the road (even though it might only be for fractions of a second)

Dave

[sweet-dentist]

Yes... it must be the ABS... kicks in really fast...

Peter

Try it out on a sandy road... or when rainy...

[mosi]

Thanks for your reply guys

[thewildblue]

Its the ABS, I think its to do with the emergency brake assist over compensating. Mine does this in silly situations, mostly feels like from the back wheels for some reason, as are discs really necessary on the back of such a light car.

Doesnt have to be slippery conditions, I thought that having the master cylinder done on the recall would sort this. It did to a degree and it happens alot less now, even so in my other car Im yet to feel the abs kick in on exactly the same routes, usually carrying more speed and alot more weight.

[s44gtw]

It is a car with a wheelbase of only 2000mm,

which has VSC+, EBD, ABS, BA all trying to do their thing,

it does feel unusual at times compared to longer wheelbase vehicles,

& also 'does not always work correctly' or appear to be able to cope with UK roads.

(its little brain just can not cope, maybe try switching the electrics off and see how it behaves)

There were Early Reported Faults concerning some of these systems, which kind of got sorted out in the steering recall,

or some other recall.

(possibly was not actually part of that recall, someone that previously have had the rough road, odd brake behaviour thing dealt with can maybe comment)

If you think there is a fault in the Braking system then have it checked/driven by a competent/trained/trusted person that will know how it should feel and behave.

(that might need to be a mechanic/technician, that does not work for a Toyota Dealership!)

george