E220 Vented Discs

[RidleyRumpus]

I have just been to see a S212 that's for sale and I was looking at the Vented discs.

I've not seen Vented discs before on these cars, should the surface be flat and smooth?

On these they almost had a ripple across the surface, it didn't look or feel like what you get from grinding you get when the pad runs out, this looked almost a uniform "ripple"

Is this normal and a way to increase surface are or do these discs need replacing?

 

[Petrol Pete]

In My honest opinion 'cross drilled' (not vented) brake discs on humble road cars is a fashion statement and will do very little to improve braking performance but do quite a lot of damage to the lifespan of the pads and discs themselves.

If the discs have any raised edges on it's swept surface (ripple) then they are worn , not necessarily worn out , but worn . If you can see ripples in the disc surface through the spokes of the alloy wheels that correspond with the drilled holes I guarantee you the side of the disc you can not see will be in worse condition.

 

[RidleyRumpus]

In My honest opinion 'cross drilled' (not vented) brake discs on humble road cars is a fashion statement and will do very little to improve braking performance but do quite a lot of damage to the lifespan of the pads and discs themselves.

If the discs have any raised edges on it's swept surface (ripple) then they are worn , not necessarily worn out , but worn . If you can see ripples in the disc surface through the spokes of the alloy wheels that correspond with the drilled holes I guarantee you the side of the disc you can not see will be in worse condition.

So they need replacing then?

 

[Petrol Pete]

If you have not bought the car yet the obvious surface wear on the discs might be a bargaining chip to bring the price down a bit to the tune of whatever MB charge for replacement . But it's not a deal breaker.

But the brakes are probably OK unless grinding and/or showing a wear lip . Not too costly to replace DIY.