brake shudder after driving on very wet road.

[som]

A couple of days ago ,during an absolute ripper of a storm (64mm rain in 30min ),I experienced pretty serious brake shudder under very moderate braking.Z bar bushes were recently replaced as were front struts,top plates and bearings.The only thing that I can see which looks even a little short of perfect is some very minor glazing on the rotors.Surely this wouldn't be the cause of the really extreme shudder.Any ideas would be appreciated because I'm obviously missing something.

[spauldj308]

Were you driving it? Say, if the brake rotors were hot, then cooled quickly by driving through a puddle, this could cause them to distort and warp, causing shudder.

[IBLOWN]

As above^^^^ I'd be putting an insurance claim in to God.

[som]

Had the rotors checked yesterday morning and they're ok.As far as getting any satisfaction from God if that had been the case,how about the poor guy that pulled to the side of the road to escape the hail only to have a tree fall on his car ,crushing him to death.And here I am complaining about brake shudder.

[spauldj308]

If the rotors are ok, and I would get another opinion, it is very common, perhaps a faulty abs unit?

[Killr6]

sounds like warped rotars to me lol

[som]

I've booked it in for Friday to have the rotors checked again and skimmed if necessary ,though they're only 7000km old and I'd been driving like a granny so they wouldn't have been excessively hot at the time.I'm still wondering whether or not the little bit of glazing that I think I can see may have caused the water to disperse irregularly though I'm the first to say that it sounds like a long shot. Thanks for your replies guys.I'll keep you posted

[som]

I'm told that the rotors have "hot spots" and that they will need to be replaced.I'm not totally convinced but I've now been told by 2 mechanics,the one on Friday being a brake specialist,that the rotors are not warped so perhaps they do have hot spots.I'll see if I get any response here before I buy new rotors and pads again. The shudder happens frequently now ,though it's not at all severe but I think that it seems to only occur when I haven't had to brake for a while (so the rotors are cool or cold ) and I am braking from speeds in excess of perhaps 100kph.eg open road.

[jughead1]

I'm told that the rotors have "hot spots" and that they will need to be replaced.I'm not totally convinced but I've now been told by 2 mechanics,the one on Friday being a brake specialist,that the rotors are not warped so perhaps they do have hot spots.I'll see if I get any response here before I buy new rotors and pads again. The shudder happens frequently now ,though it's not at all severe but I think that it seems to only occur when I haven't had to brake for a while (so the rotors are cool or cold ) and I am braking from speeds in excess of perhaps 100kph.eg open road.

Sounds like my problem.

A couple of weeks ago I replaced the back brake pads on our VX II waggon.

Last week I noticed the car shudders a bit when braking. It does not shudder when braking lightly (slowing down a bit) but shudders a hell of a lot when braking moderate to hard, or when going down hill and I press the brakes for a long time (about 20 - 30 secs onwards).

When I changed the rear pads, I took the front wheels off to check the fronts also, but did not change the pads.

I will look for "hot spots". Any suggestions on how to tell?

Cheers,

JG

[som]

Sorry mate,I have no idea.I'm still not in a rush to buy new rotors though so I'm still waiting and hoping that someone else may come up with an alternative cause. My car does not have abs so that cannot be the problem.At the end of the day if I have to buy new rotors I will but as I said I'm not that keen,mainly because I,m not totally convinced that my problem will be solved.

[pablo]

I would be inclined to let it go for a few days to see if the brakes settle down!

[jughead1]

I would be inclined to let it go for a few days to see if the brakes settle down!

Mine are getting worse, not settling down.

I do have ABS, but this is a definite shudder, felt through the steering wheel (side to side), and not the ABS cycling the brakes on and off (usually felt through the brake pedal pumping).

The car is booked in this Saturday to have LPG installed. I will get the mechanic to have a look while he has it.

Cheers,

JG

[som]

Finally I made a decision,feeling like an absolute dill for not doing this in the beginning.Had the rotors machined.The slightest skim and of course the shudder is gone.

[m1lky]

For reference sakes. Generally: If it shudders more the heavier you brake it's warped discs. If it shudders more under braking with increased vehicle speed it's bushes/ball joints etc.

[som]

That's a good description m1lky.My shuddering definitely increased during heavier braking and now after a skim the shudder is completely gone.I reckon that you and
spauldj308 both hit the nail on the head when you suggested that the discs cooled too quickly during the rain storm and caused them to warp,I guess I just didn't
think that they would have been hot enough for that to have been a problem.Anyway it's all great now cos they have been machined and the shudder is gone.I'm still going to keep kicking myself every 10 minutes or so for the rest of today for not getting them done 2 weeks ago.