My wife purchased a 2006 C280.

we put new tires on it and had it aligned. About 700 miles later the brakes started to "Pulse" in the pedal and the steering wheel.

I purchased a front rotors and pad set from FCP Groton. The car was smooth as silk.

Around 600 miles later the pulse started again. I tried "bedding" the pads but to no avail. I then had the front "new" rotors turned. After reinstalling them all was good.

A few hundred miles later the vibration was back. I purchased genuine mercedes pads for the front and rear and had the front rotors turned again. Once again all was well.

The vibration is back again. I noticed a "fluid" coming out from the upper control arms so I replaced the upper control arm bushings.

That did not resolve the issue.

The calipers do not appear to be binding.
The caliper pins are cleaned, lubed and move freely.
I have re torqued the wheels to 80ft pounds with the wheels both hot and cold.
The suspension components seem good and tight. (including tie rod ends).

Any other ideas?

Thanks in advance for your help!
Joe

There have been instances where the aftermarket rotors have metallurgical issues, i.e.; the hardness of the material varies on the wear surface, which causes the discs to wear unevenly, leading to pulsing.

Jim

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14 E250 BlueTEC black. 45k miles
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94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles

Agree with Jim. If you put on new rotors and they warped - then you had them trued and they warped again - must be defective rotors. Should be some kind of guarantee on them and the installation unless you did the install yourself.

Cleaning the scale from the hubs with a wire wheel and in extreme cases an abrasive disc, goes a long way to keeping rotors true. There is also a bulletin from MB about applying nickel based antiseize on the hub before installing the rotor to aid in heat transfer from the disc into the hub to prevent warpage.

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90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

Thanks for the replies.

The hub to rotor mating surfaces are super clean.

I also serviced the bearings.

The rotors are "Meyle" premium (or something to that effect.) Are these known to have issues?

Thanks

Joe, recommend buying rotors from a MB dealer. By the way MB advises against turning down rotors. If you prefer not to buy brake pads from a MB dealer, recommend using Textar brake pads which are the same soft material as genuine MB brake pads. Granted they produce considerable brake dust, but the brake system performs to design standards.

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Fred Hoelzle

Ferdman

Rotors from the dealer are the next step I am considering. I am just afraid that whatever is causing this to happen will also do the same to the new rotors.

I did a lot of research on the Meyle (not sure how it is spelled) and found almost non if any, negatives about them.

I am fairly certain the rotors are the issue we are feeling, because replacing them and turning them did solve the problem for a bit. It may be the "Symptom" of another issue.

As I understand it most of your stopping action comes from the front brakes. Could it be that the back rotors (instead of the front) are warped and that you only feel the pulsating on hard stops when a lot of the stopping action is also handled by the back brakes?

Far out guess.

I'm always skeptical of a "warped rotor" diagnosis. I'd bet that its among the rare events in the universe. Happens to someone else, never you. But what may happen is that the pads are stcking to the rotors, leaving behind a thin patch of brake material or corrosion. If you don't thoroughly clean a new rotor with solvent before installing, "warping" is almost guaranteed, as assembly oils and rust preventive coatings will burn into the friction surface. Same if you leave greasy paw prints on the rotors or pads. If you park outside in wet weather and don't drive it for a bit, rust will begin under the pads. So this could be a self inflicted problem.

Try this. After a normal drive, whatever that means for you, feel the center of your wheels. Are any of them unusually warm? If so, think stcky caliper. Next time you heve the problem, examine the rotors before you turn them: look for marks or discoloration.

I don't believe buying specific MB rotors will solve the underlying issue unless they are the rotors themselves. Try a different rotor from your local parts store as they shouldn't be that expensive if you are going to buy new rotors because I'm sure every single forum member is not running MB rotors from the dealer on their cars (I'm certainly not) and none are having any issues with theirs. Mine came from AutoZone a few years back and no issues.

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1990 190E 3.0L

And although off topic, I gave up on dusty, squeaky semi-metallics and switched to ceramics and life is good.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

If you don't want to pay for genuine MB rotors, which from my experience are not much more expensive than aftermarket brands, I recommend ATE coated rotors. The coating, as on the genuine MB rotors, is a light gray primer which protects the non-contact surfaces from rusting.

As mentioned a stuck caliper can cause overheating resulting in rotor warping. You may want to remove the front wheels and check that the calipers release completely, and that the caliper pistons move easily.

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Fred Hoelzle

Thanks everyone for the replies!

While I did not use a thermometer, both front wheels feel warm but not really hot.

The pistons in the caliper move in and out as they should and after jacking the car, they do not seem to be dragging.

All sets of pads (three sets now) have had nice even wear on all four.
set 1 was on car when we got it and looked almost new. Previouse owner may have sold car over this issue.
Set 2 I bought online. I may have put 1500 miles on them before I purchased set 3 from Mercedes.

The second warping was on a trip to chicago and I drove the entire trip. I know that my foot was nowhere near the brake pedal.

Please keep the thoughts and ideas coming!

I used to make large roller bearing races up to 26.5 inches in diameter.We had a problem one time after heat treating and final grinding the races grew .030".We started after that freezing the races in liquid nitrogen after heat treat,.
If you replace rotors again I would invest in cryro treated rotors.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

Get an IR thermometer so you check the rotor temps after driving.

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Prost!