bad braking vibration. AP racing calipers.

[240zRB26]

Hello All,

I bought a brand new 2023 Supra in October and got really bad brake clunking noise when getting off the brake pedal, I ignored it since I was going to install a AP racing brake kit. The AP racing kit worked well, after the proper bed in process, for a few weeks, but for 3 weeks now I've been getting a really bad brake vibration (shudder?) and loud noise. This only happens after I've driven the car for about 20 minutes and happens when approaching a stop. I checked runout on the rotor and if there were any loose bolts, but found nothing loose or out of spec. The brakes work great when cold.. When the issue occurs I do not feel vibration at the steering wheel, only the pedal.
Any help?

Sponsored

 

[razorlab]

What brake pads are you using? Did you bed them in properly?

 

[Rocksandblues]

Doubt they are bed in properly

 

[lucky phil]

looks like the bedding in was "sub optimal" as they say. During break in the pads basically lay down a microscopic film of pad material on the disk face. If this film isn't evenly laid down then you get brake judder. The fix is usually the use of a disk flex hone to remove the uneven pad layer and provide a fresh disk surface for a proper bedding in process or a minimal surface skim of the disk
faces.
I always give pads a light sand on the friction face with 400 paper on the surface plate before I fit them to make sure they are dead flat and have a clean surface for break in. But thats just me.

Phil

 

[jorligan]

The noise at the end, Is that what you are talking about? The shudder looks like bedding issues but improper bedding should not cause any noise. Is the brake pedal quivering?

 

[Insomniac]

You feel it in the brake pedal? Did you check runout on your rear rotors?

Richard

 

[240zRB26]

Hello All,

Sorry for the late reply was out of town. I did perform brake bed in exactly to the AP racing specification. I don't thinks it's brake judder since I don't feel any abnormal feedback from the steering wheel. The vibration comes from the pedal only and the loud noise. If I apply the brakes harder there's no noise. I checked all parts and everything seems to be fine. The dust shield is 1/4" clear of all components. I doubt it's bedding issues since I am getting that noise at stop then off pedal at 3mph then apply light pressure at brakes and I get that noise.

The noise is similar to a single sided piston seized slide pin. I will check the rears next and check the runout.

I have not checked my rear brakes at all, but will check there next. Will also remove the AP kit for now and reinstall the OEM brakes.

 

[sup.dc2]

I dont think your problem is in the brakes themselves. The weight shifting from braking seems to enhance the problem. At such low mileage I wouldn't rule out a ball joint fastener not tightened to spec from production. See if you can pinpoint the noise from the outside and trace it to a specific corner. good luck.

Sponsored