GR Yaris Brake vibration

Yohz78

Yohz78

Dedicated member
Feb 8, 2025
105
178
43
Hey,

Following last track day, I changed my tyres from PS4S to Goodyear eagle SS but have yet to change pads (they still have like 10-20% life in them) or to bleed the brakes.

I have no vibration when driving normally. However, if I start to brake a bit harder or to drive a bit faster, on a B road for instance, I have vibration when braking hard especially if the brake get warmer (ie it get worse). Those are no huge vibration but it vibrates enough to be annoying and stop you from trail braking.

Should I just change the brake pads straight away or is there a way to get rid of the vibration ? I have never experienced that in the past, so just curious to have your 2$.

Thanks !
 
  • Like
Reactions: micsub
Yohz78 said:
Hey,

Following last track day, I changed my tyres from PS4S to Goodyear eagle SS but have yet to change pads (they still have like 10-20% life in them) or to bleed the brakes.

I have no vibration when driving normally. However, if I start to brake a bit harder or to drive a bit faster, on a B road for instance, I have vibration when braking hard especially if the brake get warmer (ie it get worse). Those are no huge vibration but it vibrates enough to be annoying and stop you from trail braking.

Should I just change the brake pads straight away or is there a way to get rid of the vibration ? I have never experienced that in the past, so just curious to have your 2$.

Thanks !
Click to expand...
If you got vibrations from the brakes its usually the discs at fault so get them checked out.
 
  • Like
Reactions: micsub and Yohz78
Euge said:
If you got vibrations from the brakes its usually the discs at fault so get them checked out.
Click to expand...
What's strange is that the issue started a few hundreds of km after the trackday. If I had wrapped the discs, it should have caused issue before ?

Also, when braking gently, I have no vibration at all. It started after changing the tyres but I should experience vibration all the time if the wheel have been out of balance ?
 
Last edited:
  • Like
Reactions: micsub
Yohz78 said:
What's strange is that the issue started a few hundreds of km after the trackday. If I had wrapped the discs, it should have caused issue before ?

Also, when braking gently, I have no vibration at all. It started after changing the tyres but I should experience vibration all the time if the wheel have been out of balance ?
Click to expand...
I think my first port of call would be giving the brakes a clean and check for pad deposits.

If it was tyre off balance you would feel it constant at speed not just braking. try swapping wheels from corner to corner on the car, and check non brake surfaces of the rotors where the wheel face meets for corrosion, wheel maybe not sitting flush. Failing that, get the brakes checked over.
 
  • Like
Reactions: micsub
Check the disc run out. If discs get too hot they warp and cause those vibrations. I had this issue after the pads wore excessively on a track day, run out was way off scale. New discs cured it.
 
  • Like
Reactions: micsub
It does not feel like wrapped disc because I have no vibration with cold brake, it is really a strange one. However, upon closer inspection, I discovered this ... I guess I just have huge pad deposit on rear discs. it is strange because I avoided using handbrake during the trackday. But I think I used it after some B-road blasting sometime after the trackday ... may be just a rookie mistake ... I cleaned the brake with pressurized water and re-bed in the pads. It seems better, we'll see... anyone has tips to get rid of the deposit except driving ?
1000028420.webp
 
Last edited:
  • Like
Reactions: micsub
Yaris San said:
it's pad build up, almost impossible to warp disc, they're designed to glow red hot without issue, it'll pass with hard braking although might worse before disappearing
Click to expand...
It didn't feel like wrapped disc either, in such I should have had vibration all the time. First time in 13 years I encounter that ! I'll do a few bed-in session, it should be enough to clean it ...
 
  • Like
Reactions: micsub
banzai2 said:
The handbrake works on a drum brake inside the disk. I have some warped discs you can buy if you believe they do not warp.
Click to expand...
Not that I want to buy them 🙈, but would you be so kind to share some more info about those disks -- maybe it helps the community
I suppose we are talking about front disks... are those OEM or aftermarket (manufacturer?), do you happen to know their thickness / mileage and well, maybe you can tell us what has lead to the warping

I have some EBC front disks for about 60.000km, they are at 26.6mm thickness (28 new, min thickness 26mm vs OEM 25mm) and there is a noticable vibration on hard[er] breaking from higher speeds...
 
  • Like
Reactions: micsub
The disks were Tarox a brand I used to have faith in. The warping was caused by EBC yellow pads which managed to wear down to the backing plates after two track days, sabotaging the disks on that second day. I had no idea the pads would wear out so soon as they were new immediately b4 snettterton and finished half way thro Bedford with maybe 150 road miles in between.
The reason for fitting the EBC chocolate pads was that the Tarox ones had started to disintegrate which I discovered just b4 snetterton. EBC was the only option available at short notice. Tarox had advised that pads with bits missing were perfectly ok and just carry on using them and no we wont replace or even look at them!
As a result EBC and Tarox are a no for me.
 
  • Wow
  • Like
Reactions: micsub and Orion
Yeah, EBC pads are pretty much garbage

Did you check the discs for runout though? I doubt they are actually warped, probably just gummy EBC pad deposits. Heard of this plenty of times before.
 
  • Like
Reactions: micsub
So to follow-up on this topic, vibration are getting better. They still are there once the brake get warmer but it's more and more manageable. Best solution would probably be putting agressive track pads but it would be a bit of a waste since I won't track the car before next spring.

Hope it'll just disappear at some point.
 
  • Like
Reactions: micsub
Michael Knight said:
Not all
Click to expand...
Yellowstuff are in my experience. Did not try the others. I straight up lost the brake mid mountain road with my ex-impreza with Yellowstuff. The pedal went straight to the floor and I almost killed myself. I had to max engine brake + use handbrake. Since then, I don't want to hear about them lol.
 
  • Wow
Reactions: micsub
In over 25 years I've ever heard anything good about *stuff pads except from people with very lights cars (Caterhams, 106 Rallye etc.)

RP-1 were good for me in terms of performance, but not dust or longevity.

RP-X I haven't tried.
 
  • Like
Reactions: Ecsrobin
Just to hijack this thread, jsut swapping to winter wheels this afternoon and saw this on one of the rear discs. I cleaned everything over with brake cleaner (and the hub, so it’s lots neater now!) but the mark is still there. Also looks like the pad has been sticking on the handbrake and there was lots of heavy rain here recently so parked away when wet.

Similarly, plenty of pad life left and couldn’t see any visible obstruction but it looks like something has rubbed on the disc. That or a sticking caliper perhaps? Also owning a Honda however, it does feel a bit different to that.

Hopefully not warped but under heavy braking you do sometimes get a slight buzzing feel. Car is due for a service in the next fortnight so will get it checked over but curious as to what it is.

IMG_0270.webp
 
  • Wow
  • Like
Reactions: micsub and Chris007
Brake judder can sometimes be caused by variation in friction levels around the disc. This can happen even when the disc is perfectly flat and has no runout at all.
I had this happen afyer 6 months with a Fabia VRS after I fitted new discs.
Used to het judder undr hard braking or just when gently touching the brakes when coming to a halt.
New discs sorted it.
I used to work in R&D at Mintex when I was younger and it was something they found out back in the 80's.
 
  • Like
Reactions: micsub, GRavy_Baby and Dav1d
Shadowphax said:
Brake judder can sometimes be caused by variation in friction levels around the disc. This can happen even when the disc is perfectly flat and has no runout at all.
I had this happen afyer 6 months with a Fabia VRS after I fitted new discs.
Used to het judder undr hard braking or just when gently touching the brakes when coming to a halt.
New discs sorted it.
I used to work in R&D at Mintex when I was younger and it was something they found out back in the 80's.
Click to expand...
Thanks, Yeahh new discs are ready to fit this weekend (when it stops raining!). There was some corrosion on the inner surface picked up at the most recent service, so should fix it. I’m a really light braker (tend to just lift off before a corner and coast round), so the rears don’t get much use.

Any tips for bedding in the rear pads would be great btw, is there an easy way to ensure they get hot enough rather than just the fronts taking most of it? I can only think of reversing 😂
 
  • Haha
Reactions: micsub
You must log in or register to reply here.
Top Bottom
Back