Hi,

When braking the steering wheel shakes/vibrates. I removed the pads and gave the caliper a good clean last weekend and put some copperslip on the usual spots and checked the dics for wear. The discs didn’t look too thin but after reassmebly the steering wheel still shakes when braking. I’m guessing it’s new pads and discs time but before I bite the bullet and buy the parts is there anything else to rule out?

Steering rack etc, as a starter?

Wheel nuts slack?

Warped discs

Could be warped discs, or suspension/linkage issues?

Any play in any of the suspension components?

My money is on warped discs

/\ I’m with him

Warped disks

Warped disks.

Warper baby robin.

Its symptomatic of demonic possession – like in all those Stephen King movies – Christine, Maximum Overdrive and Herbie Goes Bananas and Kills Everyone.

Warped Discs… classic symptoms

Find a nice long stretch of road (flat), get the car going at a good clip… not silly just a good clip.

gently (very) put your left foot on the brake to let the pads drag on the disc whilst keeping the power on. This will put a lot of heat into the disc keep this up for about a min or until you can smell the brakes.

Foot off the brake pedal and drive normally till they cool down (about 5 mins) avoiding braking to a standstill. This “should” cure a warp.

Warped discs are normally caused by stonking up to a roundabout or a junction at warp speed standing on the anchors to stop then keeping the pedal pressed while stationary – the steel of the disk under the pads cools at a different rate thus stays expanded ergo warped disks!

Give us a clue. Is it a specific car?

thomthumb – Member

Is it a specific car?

No, it’s a generic car.

Could also be abs

But my moneys on warped disks …..

Usual caveats apply , the fact your asking a forum for what to do , id suggest taking it to an experianced professional to give it a once over instead of throwing the parts cannon at it.

Highly unlikely to be a warped disk.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Dont listen to him ^ 🙂
Warped disks +9

Measles?

Brakes don’t warp from excessive heat which is what that white paper about race car braking thermodynamics says. 🙄

Don’t think the OP is worring about brake judder on his GT 40 or Shelby Cobra at LeMans, Daytona or Silverstone

They DO warp in normal use from differing rates of cooling when stationary and the pads are left in contact with the hot disc, insulating that section of the disc as the rest of the disc in free air cools faster.. say at a junction, foot on brake whilst stationary after heavy braking up to said junction.

Cured in most cases by heating the disc back up again and then allowing to cool normally.EXACTLY THE SAME AS A WARPED MOUNTAIN BIKE DISK!

Some can be cured like that

How ever if you have followed a non french hgv driver down alp dhuez and have a slightly slipping clutch and over use the brakes to stop driving into the truck …. Nothing unwarps them. Replacing them how ever takes 20minutes 🙂

How ever if you have followed a non french hgv driver down alp dhuez and have a slightly slipping clutch and over use the brakes to stop driving into the truck …. Nothing unwarps them. Replacing them how ever takes 20minutes

And how long did it take to get the stains out of the drivers seat

I’ve never believed the warped disc theory. have you seen how thick a car brake disc is? you’d be talking a shite load of heat to warp that…

How long has it gone on for? If its got slowly worse since last set of discs where installed, its more likely to be a rusted/crap covered surface on the hub (where the disc bolts on), which gives a warped disc effect.

Worth checking the all the steering and suspension linkages etc…

Its not the heat that warps them its uneven cooling in most cases.

My parents auto box merc used to eat disks becausea my mum would hold it on the brake always instead of using park …. And she drove it like she stole it using the brake like an anchor.

We had a cracked disc on an old car in the past.

I did a few track days and had discs glowing and forever blued, never ‘warped’ one. We worked under different assumptions. It’s for the reason you stated, ie, clamping a brake on hot disc such as after a motorway slip road. However, I was told that some of the brake pad compound reacts with that part of the disc and creates uneven friction.

Not had it for years, whatever caused it must have been designed out in the most part.

A quick google supports my theory, I wasn’t lied to.

It’s transfer of pad material to disc according to EBC brakes.

I don’t believe for a second you can warp a cast iron disc through uneven cooling.

steering linkages would be something else to check, as I found out last month when reported this problem to the MOT tester.. 🙁 that and wheel bearings, in fact the wholes tearing system was pretty shot 🙁 🙁

I don’t buy it either. Mrs Gti’s Citroen C1 had terrible brake judder and that was caused by the pads having rusted to the discs when she left it after driving on wet salty roads. She also wasn’t using the brakes hard enough so they rusted unevenly and began to judder. You can get discs skimmed in situ but it’s cheaper just to replace.

Exactly the same thing is happening with her Ibiza, because she’s ill and can’t drive it. I take it out once a month and give it a good caning to work and back and the judder is cured.

I’ve always took warped discs as a term for uneven surface caused by various reasons not necessary physically the disc itself being deformed.

Discs might not be warped but could be knackered!

Had a set of discs on a smart go where there were chunks out the backs of the discs, literally chunks out of the backs, going round the disc on the back it was shiny smooth, shiny smooth, 3-4mm deep chunk out for 2-3cm of dull metal. Really odd happened on both sides, it was as if there were 2 materials laminated together and the a surface section had fallen off! Never seen it before or since brakes felt awful, they were changed pretty quick, they looked good on the front surface though

Mine developed this on the way back from France at the weekend. Also wheel judder at cruising speed. Progressively got worse even though I did the 800+ miles at no more than 60. Which was nice. Coming from right front which was running hotter than the left. Its had a disc and pad. The brake judder was so bad in the end i was driving like i couldn’t use the brake pedal, coasting to a stop which in traffic on the M1 is not easy.

I defo don’t run my brakes hard enough but then I did get brake fade at the bottom of the Col de La Forclaz so it can’t be that. It has had new wheel bearing, pad and disc and caliper all in the last 12 months. The right front wheel has been my nemesi.

Goes in tomorrow, my money is on CV joint.

The brake judder was so bad in the end i was driving like i couldn’t use the brake pedal, coasting to a stop which in traffic on the M1 is not easy.

😯

I know. They did still work if I had to. Family on board, always safe. Wheel didn’t drop off, result.

I know. They did still work if I had to. Family on board, always safe.

😯

my money is on a seized caliper.

could be…but the caliper was new in July.
So for Wheel judder at 70mph plus caused with a seized caliper, presumably stuck to disk would cause glowing disk. It wasn’t glowing or anywhere near that hot.

I’ll find out tomorrow.

if it’s not something obvious –

may be something away from the steering wheel not correctly aligned and then feeding back movement to the steering wheel. Could happen under
braking only as the load will transfer to the front and effect would be multiplied.

damaged / bent driveshaft if that’s possible?
Coils located on the shocks correctly?
cv joints ok?
Steering rack issues?
Out of line/damaged wheel?
Damaged tyre?

might be worth looking at the tyre tread to see if it’s uniform and/or scrubbing.

doctorgnashoidz – Member

So for Wheel judder at 70mph plus caused with a seized caliper, presumably stuck to disk would cause glowing disk.

Nah, not neccesarily, it doesn’t have to be dragging hard. If one wheel or disc’s noticably hotter than the other then it definitely does suggest a problem with the brakes though, whether caliper or disc or some sort of assembly issue or whatever else. Usually you’d go direct to caliper tbh but it shouldn’t be that, with a relatively new but proven part.

It’s like House MD this, you’ve got a bunch of symptoms and so far no one cause. It’s probably MRSA

It moved today for the first time since Sunday to go to the docs. And the brake made a massive bang as it moved off. So stuck caliper seems v likely.