mamono

iTrader: (7)

Hello,

70 MPH ~ 80 MPH moderate braking results in steering wheel shake.

I am running Toyota Supra front calipers with Rotora Slotted Rotors and Stock Toyota brake pads, less than 1 year old. Front suspension has Daizen control arm bushings and steering rack bushings, new lower ball joints. Everything is less than one year old. The Supra brakes do grab really well and the stopping power is very noticeable. At low speed and light braking, it feels as if the brakes grab and release at intervals.

My questions are as follows...

Is the steering shake at moderate braking during freeway speeds caused because of the ABS turning on due to too much braking force?

Does anyone with big brake kit upgrades notice something similar?

What is done to alleviate or correct for this?

tomtsops

typically my experience with this is when your rotors are a bit warped, you'll feel the vibrations when braking at high speeds, sometimes its a sign that you need to replace them or have them machined.. but then you should also replace your pads at that time..

Debonair

Tomtsops is on the money. This sounds like classic warped rotor behavior. It will get worse. If your pads are well within spec you can have the rotors machined so they are flat again. if the pads or rotors are out of spec replace them.

skaiyun

warped rotor +1

jspecdan

warped rotors fa sho. since you've got slotted rotors i don't think facing them will do too much in the long run. might want to replace them with solid vented vane rotors.

deejay

iTrader: (2)

..and use a torque wrench when installing wheels.

GS FONZy

iTrader: (6)

Do you feel any vibration on the brake pedal?

RON430

If you have the vibration at highway speed without braking, it is almost always a balance issue. A vibration when you brake is inevitably a warped rotor, or two or three. If you have both issues, you probably need two solutions.

mamono

iTrader: (7)

The calipers, rotors, and pads were all brand new when installed, less than a year ago. It seems very odd for them to warp... All new rotors front and rear and brand new brake pads front and rear...

I will have my mechanic check the brake rotors when I do my 90k service sometime this month. Much appreciated for the input.


I'll pull all the wheels and re-torque them to 80 lbs/ft, but I've never heard of over torquing of the wheels causing warped rotors.


None, no brake pedal pulsing. Just moderate steering wheel shake. The steering wheel shake seems to be proportional to the brake pedal pressure, but only happens when moderate to hard brake pedal pressure during high speed. If light pressure is used on the brake pedal, then I don't have this problem. Is there anything else? New tie-rod ends, new lower balljoints, and new steering rack bushings were installed within less than a year also.

My wheels seem to be balanced. New tires in less than a year also. I crawl over speed bumps. When cruising, I don't sense any steering wheel shake. GS drives in a straight line, there doesn't appear to be any weird alignment issues.

GS FONZy

iTrader: (6)

You should check your tires for uneven wear. Although; it could be your rotors, check everything else you mention on the previous post, plus bearings. I started to have a light vibration at around 50mph and it turned out to be the ball joints. Normally if a rotor is warped, you can feel some of the vibration on the pedal.

mamono

iTrader: (7)

Does anyone know what the mileage life is on wheel bearings when running on 20's? The 1st owner ran on 20's, so I could imagine that the bearings would take some additional wear than normal. That's one thing that I did not replace yet... I figured that the wheel bearings should have more life on them...

mpsarmi

warped rotor +2