My Karoq has done about 20k miles in the last 4 years, 95% sitting on the motorway, and she decided to developed a bad braking wobble just before we headed off travelling for a few months.  Daft question but any ideas whether this is likely to be front or rear?  I can’t tell by feel, the car just shudders under braking, but thinking most of the braking will be done by the front.

 

Taking the lazy option of just chucking it at the Skoda dealer, with a “free brake check”, no idea if this will show up warped disks but hoping so.  Lazy option is coz I’ll be jet lagged to the eyeballs having just returned to UK from Japan on the Thursday and SWMBO says it must be fixed by Saturday for a trip to my parents.  In email discussion with the dealer it’s £160 just to plug the computer in, nothing showing on the car and not sure brake wobble/shudder would show up.

 

Thoughts oh wise ones out there, fronts or rears most likely.

 

Oh, and konnichiwa from Okinawa, where it’s warm and the sun shines.  Well it did, it’s now dark and enjoying an Okinawan G&T.

I was looking into this on a 2017 A4 yesterday and found 0.07mm runout on the right rear disc... new Brembo ones!

3 thou is very little and could easily be caused by less than scrupulous cleaning of the mating faces on assembly.

 

I presume the wheel was removed to have access for the dial guage, were the wheelnuts refitted for the run-out test?

3 hours ago, DSL said:

Daft question but any ideas whether this is likely to be front or rear?

 

Without physically seeing the car, nobody will be able to say, but based on probability, my money is on the rear discs + pads needing replaced.

Consider asking your local friendly mechanic to give your discs and pads a quick inspection.

 

Won’t cost £160.

 

If the pads still have plenty thickness then there’s no panic to get new discs and/or pads.

 

Your friendly mechanic will be happy to oblige when the time comes.

If you have a warped disc, then plugging in the computer sounds like daft idea, no doubt the computer will spot a paintwork stone chip too.

 

Back in real world you might get some clue by just looking, if there are uneven brown (rust) patches on one where pad is not biting it cleanly then that is obviously the one.

 

If put on the spot in a 50/50 guess I would say rear, much harder to bend the bigger double ventilated disc, than the thinner smaller rear one

 

Without seeing the car, can't rule out a tyre defect either, bulge, lost balance weight, tracking knocked off by pothole etc

Edited 15 November, 20232 yr by SurreyJohn

Braking wobble presumably through the steering, if not then what is wobbling?

 

So if steering then almost certainly a front brake disc problem, the rears do very little work and whilst likely to corrode they would never get hot enough to warp in normal use.

18 minutes ago, SurreyJohn said:

much harder to bend the bigger double ventilated disc, than the thinner smaller rear one

 

Using force yes but when a disc distorts through heat it is stress relieving, there are many more stresses from uneven cooling of the casting on a ventilated disc to a solid one. The forces are effectively built in.

Unfortunately our local friendly mechanic is 550 miles from where the car is, and MrsDSL has banned me from driving the car until it’s fixed.  Mouse and she does before anyone asks!  🤣

 

Booked the car in for oil change and new front discs and pads, that should do for now. pretty sure it’s brake discs, shudder through the steering when braking, worse when braking lightly.  No pothole damage, and only occurs under braking.  Won’t have a chance to swap onto winter wheels before she goes in, but doubt it’s a wheel problem.   If it’s something other than discs (doubt it) then I’ll cross that bridge when I come to it.  This will prob be the last time she sees a main dealer, will be more organised next time, honest. 👍

You could have almost certainly cured the problem by aggressively deglazing the discs but its not for the faint hearted, something to remember when your new discs go the same way, not if but when!

 

Had you given more details like shudder through the steering, worse when braking lightly I would have suggested it, now it seems to be too late.

I’ve tried that but it hasn’t made any difference.  Basically taken the car up to whatever speed I can and slammed the brakes on to try and clear any crud off the disks.  Some tries were up over 60mph.  Didn’t make any difference.  Correct way?  I have an evening, and I suspect a very early morning due to jet lag, to try anything else.  Unfortunately around where the car is the highest speed limit is 40mph, unless I do it on the A3 or M25! 

May be worth a try - take it for a run to experience the judder and then park up and put the back of your hand against the wheels. A warped disc would generate friction and heat which will show up by the wheel getting warm.

If the Karoq disks are double sided i.e. vented in the middle it is quite common for the inner supporting ribs to rust away, you will then feel a disturbing pulsing of the brake pedal when braking.

On 16/11/2023 at 11:56, DSL said:

Correct way?

No, that is just tickling them, you have to do repeated full on ABS stops to a standstill from 80mph preferably driving downhill until the brakes are smoking, the pedal soft & mushy and the ABS no longer cutting in.

 

Then you need to drive to cool the brakes and do it all over again, then a prolonged drive to cool them and chock the wheels when parking for the night and do not use the handbrake.

 

Its not for the faint hearted as they will feel a lot worse but will be transformed when everything including the fluid has cooled down the next day.

 

Often I would find that the ABS did not want to cut in on the first emergency stop, a sure sign that I had left it too long between deglazing.

 

Now I do a lot of towing of very heavy trailers so the brakes get a work out and glazing is not a problem, also lots of hills around in my new location.

Not sure that’ll go down well on the M25!!  Got new disks booked in anyway, will hopefully worry re changing them in 4 years from now.👍

New front pads and discs fitted and the braking is transformed.  No more judder and car feels a lot smoother.  Pleased with the change, hope they last as least as long as the factory set.👍

 

Thanks for all the replies.👍