horrible shaking/vibrating when applying brakes
 

Hi guys, wondering if someone can point me in the right direction. I have a version one wrx import, 4 pot fronts and 2 pot rears. The car failed its mot on low front pads, which I changed. It felt fine at first, but a vibration developed shortly after when breaking. Its now no longer a vibration but a hard shake and is almost undriveable. Few things I should point out, There was a couple of siezed pistons in my front calipers which I've sorted, I didn't change the discs when I did the pads as they looked OK apart from a grove in the front drivers side. Also I believe the rear tracking is out as I've noted the inside edge of the tyres on the back have worn down, so it needs two new tyres on the back. The shaking comes through the whole car not just the steering wheel, and seems to get worse when warmed up. I'm guessingiI've probably got warped discs on front but just wondering if anyone has any suggestions what else it may be. Any advice will be greatly appreciated.

Mate definitely warped discs I had exactly the same on my 05 wrx changed the discs no problems since, mine was worth when it was warm as well, did surprise me though as my scoobys only covered 38 thousand

It's due to cheap pads,
They transfer uneven pad deposits on to the disc causing a vibrating affect when the brakes are warm.

Biggest cause of pad transfer is poor quality pads, but it can still happen by having hot brakes and sitting at the lights with your foot on the brake rather than using the handbrake.
This causes the pad to be held against the hot disc causing the pad material to be transferred on to the disc.

If it was a warped disc it would vibrate from cold at any speed.

Thanks man sounds like that's the issue then, I'll give it a shot

[QUOTE=InTurbo;11775491]It's due to cheap pads,
They transfer uneven pad deposits on to the disc causing a vibrating affect when the brakes are warm.

Biggest cause of pad transfer is poor quality pads, but it can still happen by having hot brakes and sitting at the lights with your foot on the brake rather than using the handbrake.
This causes the pad to be held against the hot disc causing the pad material to be transferred on to the disc.

If it was a warped disc it would vibrate from cold at any speed.[/QUOTE

Thanks for the reply but I didn't use cheap pads I used brembo pads

9 times out of 10,^^^THIS!!!^^^.SJ.

I used brembo pads???

Makes no difference mate,a build up of any pad deposits can cause the problem that you are having,and it is easier and cheaper to just have a good clean up and see if that solves your problem,then just going out and buying new disc.SJ.

Like I mentioned can happen with good pads if you sit at light with foot on the brake when there hot.

You mentioned it only happens when car is hot. A warped disc would be apparent from cold!

Out of interest then, what is the best way to clean up the disc?

Take off your wheels visually check inside the wheels and hub mating surfaces for deposits clean with hard brush/brake cleaner etc...to make a smooth surface as corrosion can cause excessive lateral runout I.e vibration.SJ.

That's if you have exessive disc run out,
If you have vibrations from pad deposits you can try a few methods.
You can try and re bed the pads, but from past experience this has never worked for me,
Other option thats not ideal but does work is to remove the discs from the car and give them a good clean with some very fine wet and dry sandpaper on both sides of the disc.

Last would be a disc skim or a set of new discs.

If that's works but after a while the vibrations come back then the pads are not up to the abuse your giving them or driver error by keeping your foot on the brake.

On one of my previous cars the previous owner fitted mintex pads.
I would constantly end up getting pad deposits regardless of proper use of handbrake and cooling the brakes down after a thrash.
After having to clean the discs a few times I fitted a fast road pad and the problem vanished.


Give you an idea of what your looking for, first pic is pad shape marks from keeping your foot on the brake when there hot.

Second is uneven pad transfer from pads that have gotten to hot or just crap.

Attachment 39185

Attachment 39186

warped discs 100% don't waste your time cleaning them it will make no difference, change them. or like me if theres good meat left skim them £10 a disc.

Excellent pics that show the two main culprits.

I HATE people who sit at lights etc with their foot on the brakes.....

Firstly, sorry for hijacking the thread. I am having the same issue, to sum up a severe juddering in the car when applying the brakes which is not there at first, though makes the car undriveable when warmed up. I should also mention that the DTC light is also illuminated.

I have new ScoobyWorx SWRD discs and Black Diamond Predator pads (Fitted less than 1000 miles ago) and have checked the discs for signs of deposits as posted above though none are present. Any thoughts? Could it be something to do with the ABS system?

Thanks in advance.

how did you bed your new brakes in ?

Getting up to 50mph and full on braking a few times.

Are we certain you THOROUGHLY cleaned the disc to hub mating surfaces?

A garage near us recently fitted all new brakes on my lad's Clio 197 Sport...they only got the fronts on the wrong sides, (grooved), and the disc to hub mating surfaces were far from clean when we swapped 'em over.