Thought's please on juddering whilst braking

Thought's please on juddering whilst braking

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TheBALDpuma

Original Poster:

5,842 posts

167 months

Monday 11th January 2016
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The symptoms...

When braking from 80+mph I get a lot of judder, felt through the steering wheel and the entire car, the juddering occurs until the car is slowed down to 65ish then under that you don't feel it. You don't need to brake hard for it to occur. Braking under 70mph hard, lightly, however - no judder (or very little) is felt.

It's been going on for about a year, because on normal driving I hardly ever notice it but it's starting to piss me off now, especially if I want to do a bit of a hoon!

In the last year I have replaced front discs and pads, rear discs and pads and the rear trailing arm that snapped last week (I was hoping that this having been apparently bent for some time could have been the cause, but alas no).

I think my ARB bushes may need replacing and understand that these can cause brake vibration - but would they cause really serious judder only at the high speed mentioned?

Thoughts on what else it could be?

Garages seem to just want to change the discs.

PositronicRay

26,957 posts

182 months

Monday 11th January 2016
quotequote all
When the discs were replaced was the hubs completely cleaned? If not it can cause odd wear patterns to develop.

It may be the discs, I've had to replace them prematurely before. I'm not sure if it was due to poor fitting or crap components, but it sorted it.


Edited by PositronicRay on Monday 11th January 09:48

TheBALDpuma

Original Poster:

5,842 posts

167 months

Monday 11th January 2016
quotequote all
PositronicRay said:
When the discs were replaced was the hubs completely cleaned? If not it can cause odd wear patterns to develop.

It may be the discs, I've had to replace them prematurely before. I'm not sure if it was due to poor fitting or crap components, but it sorted it.


Edited by PositronicRay on Monday 11th January 09:48
The front disc replacement never cured the problem - I had them checked to make sure weren't warped out the box, and they were fine. I'm not saying it isn't the discs, but I'm 99% certain it's something else so don't want to throw £xxx at new discs, after just forking out £600odd for new trailing arms and bits at the back, if it isn't going to defintely fix it!

E-bmw

9,105 posts

151 months

Monday 11th January 2016
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But you did not answer the question from Ray.

What he says it at least as likely as the discs themselves.

TheBALDpuma

Original Poster:

5,842 posts

167 months

Monday 11th January 2016
quotequote all
E-bmw said:
But you did not answer the question from Ray.

What he says it at least as likely as the discs themselves.
I didn't becasue a) I don't know, it was done at a garage. And b) he said that odd wear patterns can occur, so I infered it would create the problem again given time. Immediatly after the discs were replaced there was still juddering, and 6 months later the discs were checked and not warped.

Or have I missed the point?

rb5er

11,657 posts

171 months

Monday 11th January 2016
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Whenever I have had this occur it has been cured by new brake discs.

PositronicRay

26,957 posts

182 months

Monday 11th January 2016
quotequote all
Unusual but a hub could have runout. Have you tried the simple things like swapping wheels front to back?

What car is it?

TheBALDpuma

Original Poster:

5,842 posts

167 months

Monday 11th January 2016
quotequote all
PositronicRay said:
Unusual but a hub could have runout. Have you tried the simple things like swapping wheels front to back?

What car is it?
Pretty sure it's not a buckled wheel if that what you're getting at with swapping wheels? As I've done that in previous cars and it judders all the time at speed, not just under braking.

What do you mean by hub runout?

It's a Mondeo ST220

PositronicRay

26,957 posts

182 months

Monday 11th January 2016
quotequote all
It's unusual but a hub can be damaged and out of true.

It may or may not be the wheels but it's free and easy to swap them around to eliminate this.

I'd be inclined to fit new discs (carefully) to the front. Or take it to a garage explain the problem, if they recommend new discs and they don't fix it it's down to them.

TheBALDpuma

Original Poster:

5,842 posts

167 months

Monday 11th January 2016
quotequote all
PositronicRay said:
It's unusual but a hub can be damaged and out of true.

It may or may not be the wheels but it's free and easy to swap them around to eliminate this.

I'd be inclined to fit new discs (carefully) to the front. Or take it to a garage explain the problem, if they recommend new discs and they don't fix it it's down to them.
It's not though is it, they'll still charge for the work - unless I managed to explicitely agree before hand that I won't pay if it doesn't fix it but I can't imagine any garage will agree to that. I really don't think it's this seeing as I've already had them changed and it didnt make a jot of difference.

I'll look into the hub thing.

I'm not good enough with spanners to trust myself - I've done oils and filters but that's about it.

PositronicRay

26,957 posts

182 months

Monday 11th January 2016
quotequote all
In hindsight the last time the garage failed to fix it you should have taken it back.

A garage worth it's salt should be able to diagnose and repair it satisfactorily. The rear suspension clearly needed to be done, but wasn't going to cure a steering wheel vibration.

Things you can do.
Move wheels front to back, at the same time check both inside and outside faces of each disc. You're looking for an uneven swept area and brake pad imprints.

Check for even wear on inside and outside of each set of pads.

The back plate makes it awkward to see the inside face, but have a peer anyway with a mirror and torch. Try to put the car on full lock without it falling off the jack to give you a better view. It may be fruitless but it hasn't cost you anything and at least you've tried to do something.


A garage can check the following
Discs
Wheels/tyres
Worn suspension/steering components.

Other things.
If the hubs we're dirty and not cleaned properly when the discs were fitted, it could have caused both sets to fail.
If the callipers have seized it can knacker the discs.

If your not confident doing the work yourself you'll have to find an independent garage or mechanic you can trust. Ideally you'll want to demonstrate the vibration to them. Try to get some recommendations, maybe ask here on the regional forum.

stevieturbo

17,229 posts

246 months

Monday 11th January 2016
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What car, what discs etc ?

Have you even identified which corner or end of the car that is causing the problem ?

jimmy156

3,681 posts

186 months

Monday 11th January 2016
quotequote all
PositronicRay said:
Other things.
If the hubs we're dirty and not cleaned properly when the discs were fitted, it could have caused both sets to fail.
If the callipers have seized it can knacker the discs.
Surely if something was causing the discs to fail, there would have been at least a grace period of a few 100 miles before new ones instantly caused the same issue. From the OP i am assuming he got the pads and discs changed, and immedietly found that there was no difference whatsoever.

PositronicRay

26,957 posts

182 months

Tuesday 12th January 2016
quotequote all
jimmy156 said:
PositronicRay said:
Other things.
If the hubs we're dirty and not cleaned properly when the discs were fitted, it could have caused both sets to fail.
If the callipers have seized it can knacker the discs.
Surely if something was causing the discs to fail, there would have been at least a grace period of a few 100 miles before new ones instantly caused the same issue. From the OP i am assuming he got the pads and discs changed, and immedietly found that there was no difference whatsoever.
Probably, but he only notices the fault at speed, it might have been a little while before he realised.

Dave Brand

928 posts

267 months

Tuesday 12th January 2016
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A possible cause is an uneven buildup of pad material on the discs. If you're lucky giving the brakes a really hard workout may cure it - if it doesn't, it's fun trying!

It may also be a characteristic of the pads, in which case the only cure is a change of pads.

TheBALDpuma

Original Poster:

5,842 posts

167 months

Tuesday 12th January 2016
quotequote all
Not sure what Corneer it's coming from, the whole car shakes!

The brakes/pads are Mintex - the car is a Mondeo ST220

The brake judder never went away straight after having both sets changes.

Defo not dirty discs that a good braking/driving session will sort.


I will look into possinle causes of uneven disc wear, as well as the possibility of wheels being the issue.

stevieturbo

17,229 posts

246 months

Wednesday 13th January 2016
quotequote all
TheBALDpuma said:
Not sure what Corneer it's coming from, the whole car shakes!

The brakes/pads are Mintex - the car is a Mondeo ST220

The brake judder never went away straight after having both sets changes.

Defo not dirty discs that a good braking/driving session will sort.


I will look into possinle causes of uneven disc wear, as well as the possibility of wheels being the issue.
Until you can isolate where it's coming from, you're pissing in the wind.

Whilst it isnt an ideal scenario, get some proper brake hose clamps, and clamp either 1 flexi hose at a time or one axle at a time.
Clearly this needs done with extreme caution given it will impair braking performance when driving. But it will help identify where the problem actually is. Do not even think about doing it near a busy road.

PositronicRay

26,957 posts

182 months

Wednesday 13th January 2016
quotequote all
stevieturbo said:
TheBALDpuma said:
Not sure what Corneer it's coming from, the whole car shakes!

The brakes/pads are Mintex - the car is a Mondeo ST220

The brake judder never went away straight after having both sets changes.

Defo not dirty discs that a good braking/driving session will sort.


I will look into possinle causes of uneven disc wear, as well as the possibility of wheels being the issue.
Until you can isolate where it's coming from, you're pissing in the wind.

Whilst it isnt an ideal scenario, get some proper brake hose clamps, and clamp either 1 flexi hose at a time or one axle at a time.
Clearly this needs done with extreme caution given it will impair braking performance when driving. But it will help identify where the problem actually is. Do not even think about doing it near a busy road.
Trouble is his judder happens above 70! Not many of us have airfield s to play on.

The steering wheel shakes so fronts are the favourite culprit.

S0 What

3,358 posts

171 months

Wednesday 13th January 2016
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I'd be checking the TREs and or wishbone buses next, loose rack is a (TBH far out) possability, had it before on a Mk3 but the usuall issue is the track rods have play at the inner end in the rack ?

one eyed mick

1,189 posts

160 months

Wednesday 13th January 2016
quotequote all
As posted earlier by others most likley cause is dirt /corrosion between hub and disc ford were always prone to it if lots of care was not taken [I had a couple of years at ford main dealer]