Warped discs - again - W203

[merc07]

C220 W203 Sport pack - Drilled discs.

The original discs warped badly at around 40k, nothing wrong with the surface. I cleaned the face of the hubs and replaced with genuine pads and discs. Now at 80k the same has happend again.

I am not going with the genuine discs this time, may try pagid from euro car parts - if I can find the correct part number...I already have a set of their pads waiting to go on.

Is it worth changing the hubs ?

What is the cost ?

Cheers
Adam

 

[Wizeng]

I had warped discs on mine at 80k, fitted Brembo's seem OK so far.

 

[whitenemesis]

112k miles and never a problem with warping discs. What are your symptoms?

 

[Beno]

Hubs will be expensive, Check the run out of the hubs if that's OK, check run out of the discs. I had problems when I bought my W203 new discs had been fitted just before I bought it unfortunately the hubs weren't cleaned up so the discs warped in less than 5000 miles. I've fitted Pagid ones now which seem to be good.

 

[merc07]

112k miles and never a problem with warping discs. What are your symptoms?

When braking, it feels like a boat, rocking back and forward @ low speed, and juddering @ higher speed, exactly the same as before.

Guess I'll have to spend more time cleaning the hubs ?

Cheers
Adam

 

[Dieselman]

Are you sure the disks are warped?
My guess says you have friction material deposition.

 

[merc07]

Are you sure the disks are warped?
My guess says you have friction material deposition.

No, i'm not sure, I haven't measured them for run out.
What do you suggest, just clean up the face of the discs ?

 

[Dieselman]

Try flooring the throttle while planting your left foot hard on the brake and driving until the brakes get HOT.
If the problem is reduced or negated for a few days then it's uneven pad deposition. If the disks are warped you will feel pulsing through the brake pedal.

If it's friction material deposition, scrubbing the disks with a wet-stone should clean them up.

 

[markjay]

I had similar problem with a previous car.

Replacing the front hubs & bearings, plus discs and pad, cured it but only for a short while. It has been suggested to me at the time that there may be an underlying problem with a suspension component causing it.

HTH.

 

[EuroCarParts]

I had similar problem with a previous car.

Replacing the front hubs & bearings, plus discs and pad, cured it but only for a short while. It has been suggested to me at the time that there may be an underlying problem with a suspension component causing it.

HTH.

I saw on another forum (BMW) a member who had similar problems, he was lucky enough to have a tool to measure how it spins, accurate to something crazy like .001 mm - His OE ones (where he was getting feedback) was around 0.200mm and the new Pagids were 0.005mm

However, still try the cheaper alternatives first (running the pads true)

If you do need discs or pads, feel free to drop us a PM with your reg.

Pat

 

[hotrodder]

^^ A dial test indicator (link is to a google pics example mounted on a magnetic stand). Maybe a bit on the long winded side for many but... Warped- Brake Disc and Other Myths Note, it's actually an extract from one of Carrol Shelby's books and so the word 'modern' is now well out of date

 

[EuroCarParts]

^^ A dial test indicator

Thats the baby!

A bit extreme, but it done the job

 

[Beno]

That's what I use to check run out

 

[crockers]

40-50k on front discs is about their lifespan. I replaced mine at 45k and again at 97k. Were the hubs well ground before fitting?

 

[merc07]

40-50k on front discs is about their lifespan. I replaced mine at 45k and again at 97k. Were the hubs well ground before fitting?

i have a dial gauge, infact i have 3 of them in the garage ! I tried dieselmans tip, holding the brakes while driving and i rekon it made a difference, but not for long. i definately feel it pulsing through the pedal.
The hubs were cleaned as best I could, guess they have gon 40k. It's just that they went all of a sudden.
What is acceptable runout, i'll see if I can measure it over the w/e. and also give the discs a good clean.
edit
on reading that earlier posted article, measuring will show up deposits on the disc so not much point doing that.
what is the best thing to clean them with, then i'll fit new pads and try the 60 -5 bedding in procedure.......

cheers
Adam

 

[amg fan]

Instead of swapping discs again why not look for a company which regrinds the discs whilst on the car. I'm sure they'd probably be able to check how warped they are before doing the work. I've known people do this and discs be good as new ones but lot cheaper and no getting your mitts mucky!

I've heard a lot of car show rooms get companies in to do this. Maybe your brake pistons aren't releasing and are seizing on a bit, it's the quickest way to cook your brakes with the exception of a track day

 

[merc07]

Well, here is an update
After having a closer look at the discs, I decided to go ahead an replace them.

The discs were badly worn but the pads (Mercedes) were like new - 40k, obviously very hard pads.
I spent a long time cleaning up the hubs, then fitted new Pagid discs and Pagid pads purchased through Euro Parts on here.

Perfect, no more steering wheel shake, no more feeling like your on a boat as it rocks to a halt.

Just 2000 miles later however and it is now worse than it has ever been before.
The steering shakes, you feel it through the pedal and once again it 'rocks' to a halt. - not happy

Any ideas what is going on - at least the Merc discs lasted 40k but the pagid !

Cheers
Adam

 

[EuroCarParts]

Hi Adam,

Thats REALLY strange as warping 2 sets of discs (especially if 1 was nearly new) is not normal.
the discs are under warranty and would be replaced with no quibble, but i have a feeling you are just going to warp another set...

Anybody got any suggestions about the cause?

 

[w124nut]

Merc07,

When coming to a halt at traffic lights etc during a run, do you keep your foot on the brake or do you put the gear shift into neutral? I was told by a garage mechanic that if I held the car stationary with the brakes with the hot pads pressing against the hot discs, this area would not cool down as quickly as the rest of the disc and warping would result.

Not being an engineer I was not able to see fault in his argument but have since not experienced warped discs.

 

[trapperjohn]

Merc07,

When coming to a halt at traffic lights etc during a run, do you keep your foot on the brake or do you put the gear shift into neutral? I was told by a garage mechanic that if I held the car stationary with the brakes with the hot pads pressing against the hot discs, this area would not cool down as quickly as the rest of the disc and warping would result.

Not being an engineer I was not able to see fault in his argument but have since not experienced warped discs.

Never heard that before. Point taken and stored for future use. Not that I've ever had warped discs but an interesting point nonetheless.