s55sl55driver

ATTENTION SL55 DRIVERS: Has anyone experienced the front wheels locking up and skidding when braking hard. My 2004 SL55's front wheels routinely lock up and leave rubber on the road during hard braking. The engineers at MB say it is normal and the car is functioning as designed.

Please provide feedback. Thank you!

OzSL55

There was a SBC brake recall I was notified of mid last year that affected my '03 build SL55. The description of the problem kind of sounded like the lockup issue you're referring to. Maybe worth checking it out in case it is what's affecting yours.

CASL55

Are you saying the ABS isn't working? If so, that is most certainly not normal.

Jim

s55sl55driver

The wheels lock up and skid when I push the brakes approximately 1/2 of the full travel of the pedal. I am not talking about around town driving; conversely I am not talking about driving like a maniac and slamming my foot through the floor. I drive the car hard and brake aggressively to loose speed before I enter a turn. Yesterday it was about 32 degrees and I had the car out around 7am. The front tires were locking up all morning long. You can feel the brakes letting go and re-locking up almost in slow motion. Not the 30 times per second that the brochure says. In fact the brochure states that the system “prevents wheel lock up". This car leaves skid marks on the asphalt all the time.
When I was driving yesterday, I had to constantly think about how hard I was squeezing the brakes so they wouldn't lock up and skid.

Several MBUSA engineers have looked at the car they say the car is behaving as designed. As I have said before in the forums, I don't understand how they can say that front wheel lock up is an acceptable characteristic in a high performance AMG car.



My s55 does not lock up in the same conditions on the same roads.

s55sl55driver

Thank you! I will ask.

MeridianTuners

Never hapend before but i hate sl brakes. I got 15'' 8 piston brembo brakes it feels so mutch beter then stock. They improved probebly by 25%. But tthe stock brakes never locked up on me. just take the car to the dealer and go on the test drive with them.

hbluthi

Mine don't seem to be doing that?

s55sl55driver

Are you saying that no matter how hard you lay into your brakes the front tires do not flat spot???

My dealer was kind enough to let me take one of their sl55 for a few days. That car did the same thing.

At about 55-60% of the travel of the brake pedal in both cars the front tires would flat spot on the highway at highway speeds. I took the car to 90mph and then made sure no one was behind me on the highway, then I got on the brakes to simulate taking speed deep into a turn braking hard before turn in. If i got on the brakes quick and hard they would lock up right away..If I start slow but kept going the tires would flat spot as well.

On monday I am testing an 06 sl55 with the Nurburgring Calibration (AMG Performance Package) to see if the brakes are less sensitive.

My thoughts are twofold: First a car with ABS should not have ANY wheel lock up and second is the fact that it occurs in the two cars I have driven in the mid point of the brake pedals travel not at the botttom.

I am thinking of shipping the car down to Renn Tech to have Hartmut and his team see waht they can do with it.

OzSL55

Sorry to hear you are still having dramas with brake sensitivity. I remember a few occasions where the brake system seems to lock agressively in normal street driving, to the point where you thought would be thrown through the windscreen. However, I haven't noticed anything like this post the SBC recall done in Dec. Mind you I haven't attempted any freeway brake tests like yours lately. I'm a bit paranoid about hitting 144 km/h as that's 34 km/h over our speed limit here and they don't take it too lightly if you get caught.