Vibration Under Braking

[awnield]

Hi all

I'm only a newb so be gentle.......

I've had my 2004 IS200 for about 6 weeks and I've noticed that under heavy braking (particularly at speed) the car vibrates. However, none of the vibration can be felt through the steering wheel, it's all through the car. This is why I think it's the rear discs..........?

Another symptom is that when braking to a stop, just before the car stops it's as though the brakes are being pumped very slowly (although my foot itn't moving). I find myself rocking backwards and forwards in the seat.....

Has anyone got any thoughts?

Please help.

Thanks

Adam

[sparkystav]

Sounds like a sticky front caliper to me, when you've finished a journey throw some water on each brake see if ones a lot hotter than the others,

Stav

[awnield]

I've had a feel at the wheel centres after a few journeys and there isn't one wheel which seems hotter....?

Maybe a stupid question, but, if it's a front caliper wouldn't I feel something through the steering?

Cheers

[TomCooper]

Sounds like a sticky front caliper to me, when you've finished a journey throw some water on each brake see if ones a lot hotter than the others,

Stav

personnally i dont recommend this, unlikely to happen but can warp or crack discs, and ive known it to happen when people fron water on glowing red discs.

recommend just feel the wheel on each side, when mine done this 1 was alot hotter than the other.

[awnield]

I had these very same thoughts, so Like I said, I did have a good old feel at each wheel...... No noticable difference in temperature.....?

Anyone got any other ideas of should I just go for new rear discs.....?

Cheers

[TomCooper]

its unlikely to be your rear discs, it will be your front discs, did you check your front wheels after a run?

[awnield]

I checked all the wheels for a temperature difference... nothing noticable...?

If it were the front discs which were warped would I not feel anything through the steering under braking....? currently there's nothing.....?

Cheers

[TomCooper]

nah they wont be warped, its incredibly hard to warp discs under normal use.

if you start the car up from cold and use the breaks does it vibrate? or does it do it after awhile when the car (and brakes) are warm?

[awnield]

The vibration is there all the time - hot or cold.

[Steviewevie]

Are you sure that your wheels are balanced correctly ? I had a very bad vibration on my IS200 when I bought it, which I found was due to the alloy wheels having been reburbished but the wheels not being balanced afterwards, and one of them was massively unbalanced

[awnield]

When I test drove the car there was a vibration present constantly at about 65mph, I asked them to have the wheels balanced and this vibration went.

Now it seems that there is only a vibration under braking...............?

[Steviewevie]

Now it seems that there is only a vibration under braking...............?

There are lots of people here who know a lot more than me, but I personally would have thought that a vibration that only shows up under braking has got to be something to do with the brakes ?

Apparently the "sticky calliper" problem is rather common on the IS200. You can get a garage with the correct equipment to check if your discs are warped. But I wouldn't just change them without knowing how they became to be warped, because your new discs might similarly just become warped over time.

I think it would be worth getting all your discs checked to at least narrow down where the problem is. If you find just one out of the four discs is warped then at least that shows you where to look more closely.

[rig-pig]

hi m8 i had the same problem car shaking it was the rear discs and the shaking was not felt through the steering wheel

[dazz32]

If it is your front calliper`s sticking then get some new slide pins and some lith-moly grease or copper slip and replace them...doesnt cost much and you can do it yourself mate......i think there is a walk through in the knowledge section....

[TomCooper]

hmm im not sure in that case, my front right gets sticky after a while, it needs to be refurbed, new gaskets etc, but i normally pack it with copper greese and the sticky piston is fine after that.

i'll be amazed if your discs are warped, its not easy to do, frequently id have my rover discs glowing red and they never warped...

[kev dood]

Does anyone have a link the the knowledge base section to replace the sliding pins? I had a look but couldn't find it!

Plus, what about ideas for cost of parts? I think the dust boots cannot be removed so that will need changing too.

Are the pins easy to remove - I have heard they can break easily - is that correct?

[Steviewevie]

Does anyone have a link the the knowledge base section to replace the sliding pins? I had a look but couldn't find it!

Looks like it's in the Workshop forum, as opposed to the Knowledge Base. Link here

[kev dood]

ta muchly