Luminous

iTrader: (3)

Help me diagnose the problem please

When braking from speeds greater than 60mph (tested up to 100mph) I am getting quite a lot of vibration through the steering wheel. Light or moderate braking results in the same amount of shake coming through the steering wheel, heavy braking has not been tested.

As soon as the speed falls to below 60mph the vibrations disappear entirely regardless of braking pressure.

On a steady throttle there are no vibrations through the wheel at any speed up to 120mph. Only small exception is a very minor, amount of vibration at 70mph (wheel balancing)

On full throttle, no vibrations at all.

Front brakes and pads were new 2 years ago, mileage since fitting is no more than 5k. Car has routinely stood for a week, sometimes two without being driven. On first drive after standing, the handbrake has sometimes bound on, and "cracks off" under power.

There is no chance of the discs being warped from abusive driving.

I thought the problem had to be due to brake discs, but given that all vibrations go at speeds below 60mph, I am thinking it must be something else? Suggestions please

* all testing took place on non public highway

finalzero

get your wheels balanced and tracking sorted out, sometimes can also be due to incorrect tyre pressure.

Chip Sengravy

The way your car's balance reacts under braking from higher speeds is quite different to lower speeds, due to aerodynamics taking part when you lift off throttle.

I would look at the compensator overdoing it to the fronts.

scuba_doo

I'd get wheel balance done then make sure theres no rust / corrosion on the wheel hub before mounting the wheels back on ,tighten wheel nuts with torque wrench then check again , if still there check run out of front brake discs , some place's have electronic brake lathes which skim discs in place and correct disc judder , did my old bugeye worked great .

scoobyboy

it's brake judder on the front discs

KIPS

If you've broke hard while the brakes were hot and sat with your foot on the brake it takes the resins out of the pad and leaves on the disc look for a patch on the disc the shape of your pads as it could cause the brakes to slip on the glazed part causing judder to get rid of just sand it down til gone

Luminous

iTrader: (3)

Wheels are nicely balanced, although not totally analy perfect
Shouild have said car was recently serviced, problem is that same afterwards
Tracking and full alignment just done.

KIPS may have it, I have little pictures of my brake pads on my front discs Must be from when the car has been sitting. Its like a ghostly image of them in the discs, but I don't get it why I only feel it at high speed. Sanding sounds the answer....

skyline gtr v

Good man kips spot on

jasonius

iTrader: (1)

I get this, although it's not noticable throught steering or pedal, just as noise..! Very rapid, speed variable 'whump whump whump whump...!' I just put it down to the brakes not being up to the 332bhp I'm running (05 wrx), even uprated pads, fluid ands hoses didn't cure it..!

AP's before long should fix it..!

DuncanR

Had this problem on my classic wrx changed th ediscs and problem solved,

front discs were warpped i think

DeanF

iTrader: (1)

Slightly Warped discs, As road speed increases your pads will pass over the imperfection more quickly giving a more fierce vibration.
2 Choices.

Skim discs back to true, assuming they have plenty of meat left on them

Buy a New Set !!
You may find it is almost as cheap to just get a new pair as having them skimmed.

Dean

Gear Head

iTrader: (2)

Definitely warped discs. Had exactly the same on my old sti 4. I had only done 6000miles on a set of ebc grooved and dimpled discs and red stuff pads.
Fitted a set of standard discs and pads, and the problem was gone. No more brake judder.

Gutmann pug

Could be warped discs or a bit of pad transer. This is where a small amount of your pad has moulded itself to your disc. See if it goes away after a hundred miles of normal driving, if not take it and get the discs skimmed.

DaveD

iTrader: (2)

If you're not driving the car often, it may also be worthwhille to make sure that none of the calipers/pots are seized.

If this is the case, then one or more pads may be permanently held against the disc, causing overheating, and leading to warping. You could check for this by looking for variation in pad wear (ie; is one pad more heavily worn than the other?).

ARM-Scooby

i would say warped discs, just a guess though!

https://www.scoobynet.com/group-buys...ml#post6718641

might be a help?

cookstar

iTrader: (6)

Speaking of waped discs mate, you remember how much vibration mine gave, EBC rubbish again.

Cracked right though the disc.

Standard discs back on now, prob solved, car actually stops now

Yamarashi

My vote is either for warped discs (they dont have to be driven hard to become out of true!) or a wheel bearing(s) as this has the same affect until the clamping action of the pads hold the wheel stable at lower speeds.

markwild

I did get this with my old classic once - I had godspeed 335mm brake disks fitted and some 18" alloys. The alloys had a particularly large chamfer on the inner register part - and the disks were thicker on the hub, leaving less register for the wheels to sit on - this combination meant that the balance felt slightly out and this was VERY amplified under heavy braking, as the wheel would de-center itself slightly. Took ages to track down - then the 2nd gearbox blew up before I really fixed it ! ;-)