suspect warped front discs

whiteman · June 27, 2018

I have had new discs on the front of my IS200d for approx. 5000k, about 5months, I have noticed over the last few weeks that they seem to be warped again, I have done all the relevant things, checked front sliders and pistons are free also sorted the rear sliders as they were rusted in and sliders free, I just find that after 5 months they are warped. They are brembo discs and pads as I don't put cheapos on. I have been in touch with eurocarparts about the problem but have not heard anything yet. Has anyone else had the same problem or any ideas.... ?

Verbout · June 27, 2018

I believe the consensus of opinion is that discs don’t warp.

I’ve never experienced warped discs on any of my cars.

The issues are usually caused by dirty hubs not cleaned prior to new discs being fit, or the job not being done properly, or faults with the wheel or tyres.

whiteman · June 27, 2018

I have fitted many discs to cars and it has been perfect for at least 5 months so none of the above can be at fault,

Linas.P · June 27, 2018

are they drilled, slotted or any other way "Cool"?... my driller disks are 100% warped and cracked. Took a single stop from ~140MPH to around 90MPH on German autobahn and they got badly warped and I can see cracks around drilled holes. Just accepted that as part of looks.. 😄

On serious note next time I am going for C-hook, bet never for driller design

whiteman · June 28, 2018

they are standard discs, 😎

NemesisUK · June 28, 2018

You need to use a dial gauge to check the run-out. You need to mount the disc on a known true surface though.

That said I've never experienced warped discs, ever. I've had vibration on brake application, turned out to be pad material deposited on the disc. A couple of heavy stops from speed sorted it out.

I did have issues with a SEAT many years back where the dealer changed the discs due to wear and within a month I had pulsing and vibration on braking. Discs swapped out under warranty. All well for another month or so, then vibration. Again new discs, again same problem. Finally the dealer contacted VW/SEAT technical only to be told the hubs need to changed, if they can't be cleaned up properly. New hubs and discs fitted, no problems over final 5yrs of ownership.

is200 Newbie · June 28, 2018

Some things to check as its unlikely that the brembo discs you have bought and fitted are warped.

1. Make sure they are genuine

2. Make sure the mating faces (disc to hub) are clean and no dirt or rust remains

3. A sticking caliper will apply heat when driving and could cause the discs to warp when stationery with brakes applied - have you actually checked the caliper piston movement

4. If theres a vibration through the steering wheel then the issue is with the front discs - if its through the seat then its the back discs

5. Check the ball joints are secure - worn ones will cause a vibration when braking and possibly slow speed

6. Check your tyre pressures and for corrosion (with tyre off) on the INNER wheel as if there it could cause a slow puncture and a vibration when pressure is low.

hondansxr · November 26, 2018

hi i have the same on my wifes 250 replaced them with quality disc pads done 10k and there is a flutter , i noticed when i did her rear pads the caliper was a pita to remove i greased all the slides etc , it may be the rears arent working and putting more effort into the fronts as there was no issue when new , try looking at your rears or get your local garage to put it in the rollers and check the rear efficiancy

The-Acre · November 26, 2018

7 hours ago, hondansxr said:

hi i have the same on my wifes 250 replaced them with quality disc pads done 10k and there is a flutter , i noticed when i did her rear pads the caliper was a pita to remove i greased all the slides etc , it may be the rears arent working and putting more effort into the fronts as there was no issue when new , try looking at your rears or get your local garage to put it in the rollers and check the rear efficiancy

If you look at the tutorials/guides on YouTube for replacing discs, it surprises me that the vast majority don't even mention cleaning the mating faces. This can make huge difference.

hondansxr · November 27, 2018

if the mating surface ihas debry on it it will cause wobble from 1st application of the brakes not 5-10 k miles later ?

The-Acre · November 27, 2018

10 hours ago, hondansxr said:

if the mating surface ihas debry on it it will cause wobble from 1st application of the brakes not 5-10 k miles later ?

Absolutely. Even when a tyre is changed small amounts of rust flake can shift at the rear of the disc. I discovered this myself a couple of years ago after I had some work done. I had a slight wobble with slow braking so I took the wheel and disc off, cleaned the surfaces properly and all was back to normal.

BillNick · February 5, 2019

People that have continuing issues after multiple sets of discs and pads must have something out on their hub - albeit minute.

You can get your discs skimmed on the car which will remove any run out caused by the car it is mounted to - rather than the disc itself.

My brakes have been pulsing when I push them hard. I had new rear pads fitted about 10k ago, discs were not replaced. Most recently I had new front discs and pads fitted which were OEM Lexus. The pulsing only occurs under hard braking - in fact I brake softly on purpose because I hate the feeling of the pulsing when it happens. Plus I don't actually stop as quickly as I probably should because the brakes clearly aren't seated 100%.

I am going to get the rear discs skimmed. I don't have any steering wheel wobble and all other brake parts have been replaced barring the rear discs. So my theory is pay for the rear axle first, then if the pulsing is not cured, pay for the front also. I am also thinking (though have no confirmation) that if the rear is the problem that is why it only happens when I press hard on the brakes as this will push more onto the rear than usual under soft or moderate braking.

Or it could just mean that the imperfection is magnified as the pads are pushing further and further into the disc....I dunno. I just want smooth and effective brakes lol.

Ill report back after the skim.

Linas.P · February 7, 2019

Let me know how it goes, because I was thinking to skim my disks for a while as well...

Problem is that the only place close to me which does it.... is Mazda dealerships and even though they "authorised" SkimMyDiscs place they don't really keen on doing other makes.

jackcramerr · November 7, 2019

Is skimming cheaper than buying new disc?

Barry14UK · November 8, 2019

This was my experience with a 5 series BMW but same principle and same problem - I will relate.

When I bought the car the front discs were worn and rusty. I thoroughly cleaned the hub surfaces and the contact area of the inside of the wheels. calipers, piston ends, sliders etc before and lubricating where appropriate before fitting a well known make of aftermarket rotors and pads. These wheels were correctly torqued using opposing progression. It was OK for maybe 2000 miles but by 3000 miles judder and vibration was so severe that I took the car to have the rotors skimmed while still in place and the pads were ground flat and reused. The cost of skimming the rotors in place was just over half that of buying new ones. However, the same thing happened again and at the same sort of mileage. This time I decided to buy some new rotors from BMW and use ATE pads (of which I had had a good experience on a Mercedes.) These have done about 12000 miles now without problem and the car had the same tyres and tracking throughout.

I don't brake for long and hard to the extent that the rotors would get to the very high temperatures the rotors would need to reach before there was a chance of them warping. The pads were free to move and run out checked on all occasions replacement rotors were fitted. This leaves the more usual possibility of pad material being picked up by the rotors and partly transferred to and fro between the two. Maybe the original pads I fitted were not good. Also, perhaps I did not break the pads in well enough or another possibility is that after the rotors were quite hot I held the brake on at traffic lights or for others reasons whilst stationary allowing the transfer of pad material.