belarus27

Hi all , went to Lake Tahoe , and noticed that going down hill and applying brakes at 55mph and up
my steering is shacking very unpleasant.
i thought it was the warped rotors but i do have a new ones that i installed about to weeks ago...so i doubt its that.
also rear ones were changed about a year ago they all seems fine.

one thing i noticed though which may relate to this issue is that when the car is off , and i turn the steering wheel left to right and right to left it makes a sound like something is loose.

what can cause a vibration on high speeds when braking ? any ideas?
im suspecting a steering gear actually , but before i take it to the shop i wanted to see what others think.
thank you!

Dane500

Its the front brake rotors. They have slight warp. From what I've read there seems to be an issue with mb rotors. My 13 does it above 50 and exaggerates as they get hotter. Being in this industry for quite some time, my "over the internet" diagnosis is rotors.

S. Madman

if you can find my thread about the brembo NAO pads and rotors I bought, they have been awesome. The factory ones after a couple of hard stops started vibrating.

The 2014's switched to the same pads, and they don't complain about them as far as I have seen.

KEY08

^ Yes, the 2014 does not experience these issues with pulsing stops.

S. Madman

KEY if you look on you build sheet on LASTVIN.com do you see Q06 NAO BRAKE LININGS WITH NO LOSS OF BRAKE FORCE

Those are the brake pads needed.

pierrejoliat

I have QO6 brake linings on my 13

S. Madman

I wonder if they made the switch to them on '13 and up.

pierrejoliat

Yes, I was wondering as well, I also have drilled rotors and they are noticeably larger than my 12"s rotors in the front. The back looks the same. I believe my 13 stops faster also. could be part of the Sport package or AMG package? My 13 has all the AMG options without being an AMG, Wheels, Steering wheel, ground effects, 677 suspension, and rear air dam on trunk. Also unrelated my 12 gets way better gas milage than my 13, with both in eco, I get 27 average in the 13 and 31 in the 12.

S. Madman

Do the calipers in the front look the same?

DFWdude

Is the Q06 NAO package particular to E550 V8s? My 2016 V6 Sport does not have this code... not that I feel left out in any way.

I like Akebono pads and believe that is what I have on my car. I swithed to Akebono pads on my C320 several sets ago and haven't looked back.

S. Madman

I am not sure what they used in E350 but pierrejoliat has a 13 E350 and he says he has them.

I thought they were exclusive to the E550, but now I don't know.

KEY08

I do not have the QO6 code listed in any of the VIN searches I have for my car. I just did the LASTVIN search and not there either. Perhaps it's just a standard for the later E550 4Matic. My brakes have always been great and I believe the pads are Akebono. The Brembo front calipers are pretty massive.

S. Madman

Look at this one https://www.lastvin.com/vin/NLpwWEbW5Zq2Bz8a5 I wonder if it random.

belarus27

I just chamgedchanged the rotors a week before the trip.
so they brand new...

S. Madman

And the pads?

belarus27

yes when i was replacing rotors and pads i cleaned them and greased them..they looked fine ,i was able to press them in to fit the new pads no problem.

belarus27

I just checked and i also do have this Q06 Nao brake linings.. does that mean i need some specific pads 🤔?

belarus27

A little observation... before i Had GG brake pad rating with the new rotors i got FF rating which can withstand higher Temps. But they both shimmy the same.

Im guessing pads and rotors have nothing to do with my case.. as i only feel the SHIMMY in the steering wheel not the brake pedal.
im gonna take it to the shop next week.. but im thinking either the steering rack or control arms.. as i replaced them with not oem ones about 50k miles back.

belarus27

Yes pads as well.
this is my 4th time i think doing so eversince i got the car with 32k miles. Now its 156k lol

pierrejoliat

Yes mostly, I have a black plate with the MB logo on it on the 13 but the calipers are the same, the 12 has solid rotors and the 13 has cross-drilled rotors that are slightly larger in diameter. My 12 does not have QO6, but it's listed for the 13.

S. Madman

Same here it was only on the steering wheel.

My pad and rotor combo cured that.


Also look for debris on the inside part of the rotor. Another thing you want to avoid is throwing water at extremely hot rotors (is car wash or sudden puddle or rain). That will really mess up your breaking system.

Next inspect the rotor, and see if it looks shinier on some parts more than others. That would indicate a stuck or failing caliper, or that metal from the pad is stuck on the rotor.

If it got better when the new ones were installed, and then it got bad again, I am almost 100% sure its your brakes.

LILBENZ230

I've heard the theory of water on hot rotors being bad, but I have washed my car (and every car I've ever owned) after drives with brakes so hot they steam/evaporate water instantly. If this could seriously damage a braking system, it would do that to every car through every automatic wash in the country.

Perhaps if you've tracked the car to the point you're boiling fluid and near brake fire.. but in normal driving, nonsense.

belarus27

Do you mind sharing what rotors and brakes did you get? brands?

i went today under the car to check tie rods - no play (was able to twist it by hand , not sure if its okay to be able to twist them by hand , since its got a ball joint (speaking of outer) but otherwise all solid , CAN SOMEONE CONFIRM THAT ITS OKAY FOR THEM to be manually twisted PLEASE????? THANKS)
control arms - all solid no play
all of the sway linkages and mounts - no play
inspected rotors and brakes - all smooth no grooves or anything obvious
also double checked and tightened wheel bearing , steering became a little stiffer but made no change to braking.
tires are still in a decent shape.
the only ONLY is the steering column makes a little clunking noise when car turned off and stationary (steering wheel left to right) right in the steering gear or linkage by it.
did balance my tires before i got the new rotors and brakes
and while driving straight its smooth as well.

very annoying , but will take it to a shop on monday.
thank you people.

550x2

My 14 E550 coupe had the rotors warp several times under 10k miles. I switched to Stoptech rotors and aphid pads and never had another issue.

belarus27

thank you for the info , ill see what the shop will say and go from there...might be buying new rotors and pads once again lol