Vibration when braking

[Funkyboy]

Hi all, 14 plate E250 heavy vibration through floor of car and brake pedal but not through steering wheel. Front discs and pads are 4 mths old rear 14 mths. If it was front suspension or discs wouldn't the steering wheel shake as well?
Thanks

 

[brandwooddixon]

Usually vibration through the floor or seat points to the rear. Yes I would expect some feedback through the steering if it was front, but some systems fitted to the steering now may reduce what is felt.
Anything felt through the pedal when braking?
You could jack up the car, remove the wheels and inspect the discs, also check for friction spots by rotating by hand after pumping the brake pedal.

 

[Funkyboy]

Yes the vibration is heaviest through the brake pedal

 

[brandwooddixon]

Assuming that the ABS isn't cutting in then I'd check the brakes.
I know that the brake discs are only 4 months old, but I'd pump the brake peddle then jack the car up to perform an inspection.
Test for loose components - grab the wheel top and bottom, push/pull opposite sides to see if there's any free movement, same again left & right. This is checking for loose bearings and suspension parts.
Remove the road wheels and try to turn the discs by hand, looking for spots of higher resistance to turning. This is checking for "warping"/high spots of pad material on the disc.
Start with the front, remember to secure the car from moving, especially when checking the back wheels as you'll need to have the parking brake off.

 

[S500 Pete]

I had a similar problem that turned out to be a badly seated disc which warped both the disc and the hub. Replaced both and it is now fine.

Thanks Alex at AMF for the suggestion