ABS causing shuddering?

[SiliconAngel]

When my ABS kicks in I've noticed a nasty shuddering / grinding. The other day I drove over a storm water grate while braking and after the minor impact it felt like I was trying to stop the car by pushing a loose bolt against the rotor, ie ineffective and quite noisey. Coming off and reapplying the brakes works fine, but usually when ABS is kicking in its precisely because you don't have much room to brake... Is this a problem anyone's familiar with?

 

[bradc]

Try braking again on grass or gravel with all 4 wheels on the loose stuff and see what happens then. My ABS is silent when I hit the brakes hard on tarmac, when it is individually pulsing the calipers (mostly the fronts) but when I am sliding around on gravel the pedal feels a bit different and I hear a bit of grinding as well. It is especially noticable when sliding around on grass because you don't have all of the stones bouncing around everywhere.

 

[gorgath]

Also, yo might wanna check your reluctor rings if it is missing a tooth.

 

[frozen]

Also, yo might wanna check your reluctor rings if it is missing a tooth.

can you please explain that in a way that the less knowledgeable such as myself can understand hehe


i think i may have a similar problem... moreso when the car gets a bit airborne on non-flat roads while braking

 

[bradc]

There is a ring on the driveshaft that has a series of teeth on it. If one of the teeth is missing it will confuse the abs system as it will think that wheel has breifly stopped turning.

 

[gorgath]

There is a ring on the driveshaft that has a series of teeth on it. If one of the teeth is missing it will confuse the abs system as it will think that wheel has breifly stopped turning.

indeed in which I have been through.

 

[Guest]

it could be something as simple as warped rotors, or is it only when abs kicks in? if its the rotors they can be machined, hopefully thats the case, or something just as easy to fix

 

[SiliconAngel]

In the interest of clarity, no its not rotors - I have RDA dimpled and slotted rotors front and back that have only done about 10k of purely street driving. It only happens when the ABS kicks in - I know what that's meant to feel like, but it feels 'wrong' in my car...

Thanks for the suggestion Irwin, I'll check the reluctor rings hopefully on the weekend.

I'd love to try your suggestion Brad, but can't think of anywhere grassed I could take it to try that - if I got caught doing that on a park I could have my car confiscated under our 'anti-hoon laws'

 

[Guest]

I've only felt the abs kick in on ice and it's very juddery then. If it's working at any other time I haven't noticed it.

 

[bradc]

Trev - isn't there like a shit load of sand between you and Sydney that you could do some skids on?

 

[frozen]

mine judders alot when the car is balancing on 2 wheels (going up a driveway, front left and rear right are sometimes the only 2 on the road when i press on the brakes if ive accellerated up to the driveway pretty quick)

 

[leebutts]

mine judders alot when the car is balancing on 2 wheels

You mean when you do this?

 

[Guest]

You mean when you do this?

Don't worry about ABS, what about the AYC!!?!?!?!