causes of brake shudder

barryogen · Post by **barryogen** » Wed Jan 10, 2007 1:32 pm

Hi guys, bit of a pickle with My Mrs has an Altezza with a brake shudder that is only noticable when going down hill on right hand turns.

Wheels are balanced, alignment has been done since the new tyres, and it seems to be a lot less than it was prior to the tyres.

It has had the pads done recently with no change, and also had the rotors skimmed in an effort to find what is causing it, but that made bugger all difference

It is still there.

Any ideas guys cos I'm fully out of them.

TRD_ZERO · Post by **TRD_ZERO** » Wed Jan 10, 2007 3:30 pm

Warped disks maybe

TOYROTA · Post by **TOYROTA** » Wed Jan 10, 2007 3:33 pm

im probibly wrong but wouldnt a faulty abs sensor cause a shudder under brakes?

barryogen · Post by **barryogen** » Wed Jan 10, 2007 3:35 pm

covered the warped disks(sort of) with the rotor skimming, it's meant to take it back to a flat surface without having to replace them, might just have to get a price from revhead for a new set for the front.

They're about $300 a set(2) arent they?

no idea on the ABS... hence my posting here with what we've tried.

Punter · Post by **Punter** » Wed Jan 10, 2007 4:50 pm

Could be a hard spot on one of the rotor.

MrOizo · Post by **MrOizo** » Wed Jan 10, 2007 4:52 pm

s the shudder you feel mainly throught the brake pedal or the steering wheel or both?

Adydas · Post by **Adydas** » Wed Jan 10, 2007 5:13 pm

You say breaking down a hill, your sure your not breaking hard enuf to slightly apply the ABS? or is it not an ABS type shudder?

If not perhaps a good time to do a replacment of the pads and fluids?

Website · Wed Jan 10, 2007 9:38 pm

as Cliff said change the fluid,
also may pay to check wheel bearings and wheel balance, or even alignment

Alex B · Post by **Alex B** » Wed Jan 10, 2007 9:50 pm

Read it guys, hes just had the pads done, and alignment. And it takes quite a bit for ABS to start reacting. Unless its faulty, in which case the light should be staying on.

fangsport · Post by **fangsport** » Thu Jan 11, 2007 6:21 am

pyro_sniper2002 wrote:Read it guys, hes just had the pads done, and alignment. And it takes quite a bit for ABS to start reacting. Unless its faulty, in which case the light should be staying on.

not necessarily. had a AE110? wagon with ABS fault that passed damage cert with a clean sheet. has the Altezza been damaged in the right front? due to the fact you have already done the obvious to the brakes, i'd be looking at damaged bushes, control arm or ABS. maybe there is some crap around the wheel sensor that is causing the ABS system to over-react?

barryogen · Post by **barryogen** » Thu Jan 11, 2007 7:25 am

Thanks for the replies guys.

The shudder is through the steering wheel mostly, feels like alignment when it happens, but take the foot off the brake, and all is perfect.

Definately not braking hard enough to trigger ABS, it is more noticable under soft than hard braking, as in going down a steepish hill holding the car under 110km/h because theres a camera at the bottom of the hill.

Fluids were done with pads.

No ABS light on, havent even noticed one on the dash, will check the manual when I get home.

The car is an import, there is no visible damage, and according to my mechanic it was one of the tidiest ones they had seen.

Will give all the suggestions I haven't tried a go, failing that, I guess I'll replace parts until it fixes it.

Incidentally, what does a buckled wheel do? Could it give these symptoms? I've heard that they can be balanced and everything, but still do some odd things.

aesc · Post by **aesc** » Thu Jan 11, 2007 10:15 am

I've been told that you shouldnt have Toyota rotors skimmed/machined as they are very close to the minimum thickness as they are. So by having them skimmed they are very possibly below the minimum thickness, and that may be causing the problem.

But the old lady had a similar problem in her BMW recently, ended up being that some bushes where worn. Could be something to look into

pc · Post by pc » Thu Jan 11, 2007 11:06 am

Might be a flat spot/dicky spot on the tyre. Try changing the wheels over (left to right) on the front and try the same corner. If the shuddering changes to when turning left, then it probably is the right hand tyre.

OMG so shiny! · Post by **Dell'Orto** » Thu Jan 11, 2007 3:49 pm

aesc wrote:I've been told that you shouldnt have Toyota rotors skimmed/machined as they are very close to the minimum thickness as they are. So by having them skimmed they are very possibly below the minimum thickness, and that may be causing the problem.

Thats quite likely, I know most of the Toyota rotors only have 1mm of tolerance before scrappage.
Maybe get a mechanic to check the thickness?

THA SHZ · Post by **THA SHZ** » Fri Jan 12, 2007 8:51 pm

it really sounds like a warped disc , also do u have mags on it ? if u dont have locating rings it can cause that to happen . also another thing to check is if ur ngine mounts are ok ?

Bumpy · Post by **Bumpy** » Sat Jan 13, 2007 7:31 am

I replaced the brakes on my turbo starlet, couldnt skim them cause they were too thin so I went to BNT, there is one on Summerset St in Frankton, Hamilton.

Cost me around $80 a rotor, and I changed everything over myself.

If you're gonna go and buy some new rotors, measure the diameter of the ones on your car, so you dont much around with the wrong ones.

I had to wait another 10 mins fore them to find the right ones, but saved me BMXing back to the shop ...

Post by **Mr Revhead** » Sat Jan 13, 2007 9:52 am

easiest way to get the right ones is go to toyota

just as cheap as BNT

but yeah check for bushes as well. also the skimming may have been stuffed up. have seen that before

Perky · Post by **Perky** » Mon Jan 15, 2007 3:16 pm

Here's a long-shot: check the wheel-nut tightness.

Mechanics usually do wheel nuts up too tight and I read somewhere that this can put a warp into the brake discs. Toyota recommends 76 ft/lb for my car.

barryogen · Post by **barryogen** » Tue Jan 16, 2007 10:16 am

replaced the front rotors for $250 + labour, and the problem has gone.

Mrs happy once more