Brake juddering

[mercpanic]

c-class 203, 48,000 miles
Took to Mercedes, for scheduled repairs, also told them to do mot. Car failed mot, they said rear offside break judders severely & rear nearside parking brake records little or no effort.
Took car to independed garage, and they said it is fine.
Mercedes then put car again on their rollers, and insist there is a problem. They say there is corrosion on the back disc.
Any ideas ?

 

[Blobcat]

Hi & Welcome,

Have you had a look yourself? If you leave the car parked with the parking brake on then this can stick to the disc which becomes damaged when you drive off. Discs are consumables andnot that expensive so I would change them.

 

[television]

The parking brake independent from the disc and are inside the rear drum part.Rear brakes have only 28% of the braking force, and if you are a light driver they will corrode, sometimes bad enough to fail the MOT as corrosion causes a reduction in braking surface area. With parking brakes,these can go for years untended,but do rust including all of the linkage.

I would rather have good brakes than an MOT.

Malcolm

 

[mercpanic]

What makes me a bit suspicious is that the car had an A service 2 months / 3000 miles ago and a B 9 months/10000 miles ago and none of this was spotted. Also, I drive 30 miles to work and 30 back every single day and have not felt any noise or deterioration in brake efficiency.

 

[Blobcat]

A service they don't take the wheels off.

 

[mercpanic]

But when they made a visual check shouldn't they have spotted corrosion marks ?

 

[Blobcat]

No as it's inside, as per Malcolm above.

 

[mercpanic]

I'm really glad you people know so much about these things.

So, I guess you agree Mercedes are being honest about this. Now, they want to charge £150 for the repairs (originally they wanted £370 !!!!). What do you think ?

 

[Blobcat]

£150 is not bad, when you think about how much time/effort/cold/wet you would have to endure to do it. Maybe I'm getting lazy. I used to be up until 4am fixing cars on a Monday morning so I could get to work in the good old days.

 

[television]

Are, I think we are talking cross purposes here.

OK the corrosion and MOT only applies to the disc part and can be seen through the wheel, Brake judder is not part of the MOT, the parking brake is.

I think on re reading I would let the other garage do the MOT, as you say you use the car every day, if the brake judder becomes worse,change the disc then in pairs.

If the garage that said it is OK, let them do the test, its a simple job to change the rear disc at anytime, as said earlier, they do have a hard time, I have had them fall apart on an everyday car.

Malcolm

 

[BarryG]

Warped or not warped?

Found this after a previous thread be warned it mentions the dreaded *Warped* word several times
https://www.burtonpower.com/default.aspx?/technical/tt_brakes.html

Scroll down to "brake juddering"

Barry

 

[television]

Found this after a previous thread be warned it mentions the dreaded *Warped* word several times
https://www.burtonpower.com/default.aspx?/technical/tt_brakes.html

Scroll down to "brake juddering"

Barry

I can wait, you will never know why-when-how- :-( :?

malcolm

 

[mercpanic]

I have this plan: Take it to Mercedes, let them strip the car, and then have a look. But I have no clue what to look out for...

 

[mercpanic]

By the way, the www.burtonpower is VERY SCARY.

 

[television]

I have this plan: Take it to Mercedes, let them strip the car, and then have a look. But I have no clue what to look out for...

Very expensive

Malcolm

 

[mercpanic]

I've gotten them to the point where they'll do that much for free. It's just that they want £150 to fix it if there IS a problem, and we are only talking one wheel and the parking brake.

 

[mercpanic]

Just managed to have a good look at the car in bright sunlight. Well, the back o/s disk looks really rusty, but the front one isn't looking that good either.
Is that something that could have developed in the past 3000 miles ? If not, shouldn't MB have spotted in in the last service ?

 

[television]

Just managed to have a good look at the car in bright sunlight. Well, the back o/s disk looks really rusty, but the front one isn't looking that good either.
Is that something that could have developed in the past 3000 miles ? If not, shouldn't MB have spotted in in the last service ?

If the car has been out in the rain it will look rusty, ignore the brown discolouration, we are talking about pit marks and holes in the surface of the disc.

malcolm

 

[mercpanic]

No holes. Just, both o/s disks look very rusty/muddy. It did rain and the car is parked with the n/s next to the pavement. But I tried rubbing the brown bit with a tissue and it doesn't really come off.

How can I spot the holes etc. if they are behind the brown bits ? Should they be REALLY visible ? Or just little black dots ?

 

[Blobcat]

When it's light again take it for a short drive and use the brakes to clean off the discs. Then have a good look at the discs, they should be smoth without any pitting. Slight grooves are ok. Just don't touch the discs as they will be quite hot.