airmatic or SBS problem...not sure
10-27-2009, 05:25 PM
#1
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06 E500 sport
airmatic or SBS problem...not sure
06 E500 with 40k miles...
When I'm driving along on a smooth road and I hit the brakes lightly...the rear of the car pops down a bit. It's like someone jumped on the trunk...very abrupt.
I recently had the brake fluid changed. What I was thinking is that an air pocket in the rear brake lines is causing the SBS to activate the rear brakes more on tip-in. Is this possible?
I should add that the car is empty (nothing in the trunk), no loose lug nuts or anything weird. It drives absolutely brilliantly except for this annoyance. It's most noticeable when you barely touch the brakes (as in just resting your foot on it with 2 lbs of force, preemptive to actually decelerating. If you hit them for a normal stop (like a stop sign), you can feel it, but the effect is greatly reduced.
When I'm driving along on a smooth road and I hit the brakes lightly...the rear of the car pops down a bit. It's like someone jumped on the trunk...very abrupt.
I recently had the brake fluid changed. What I was thinking is that an air pocket in the rear brake lines is causing the SBS to activate the rear brakes more on tip-in. Is this possible?
I should add that the car is empty (nothing in the trunk), no loose lug nuts or anything weird. It drives absolutely brilliantly except for this annoyance. It's most noticeable when you barely touch the brakes (as in just resting your foot on it with 2 lbs of force, preemptive to actually decelerating. If you hit them for a normal stop (like a stop sign), you can feel it, but the effect is greatly reduced.
Last edited by xr650rguy; 10-27-2009 at 05:27 PM.
10-31-2009, 05:30 PM
#3
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Did you look at the rear suspension? I would think that if the airmatic is at normal height and there is no warning message in your display then it should be ok. Same with your brakes. Did you replace the brake fluid or did a mechanic do it? I would take it back if you did have it serviced and have the brakes bled. Other than that i wold think it might be a link or bushing. Good luck.
10-31-2009, 06:53 PM
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06 E500 sport
I was thinking a link or bushing, too...but...it doesn't do it all the time.
it's like the feeling if the SBS only stabbed the rear brakes an instant before the fronts. The rear end drops due to the suspension geometry. It doesn't do it all the time (or should I say, sometimes more than others). Light pedal pressure really makes it noticeable.
Everything seems tight under there, though (totally confused)
it's like the feeling if the SBS only stabbed the rear brakes an instant before the fronts. The rear end drops due to the suspension geometry. It doesn't do it all the time (or should I say, sometimes more than others). Light pedal pressure really makes it noticeable.
Everything seems tight under there, though (totally confused)
11-01-2009, 11:08 AM
#7
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When you apply light pressure to the brakes (as you said), does the car slow down noticeably? Or does it only make the sound? Lots of people looked at my car for my front suspension noise (including myself) and it seemed tight to me too. Everyone says that everything seems tight and that i should start swapping out parts to see which works. Although it may seem ok, check bushings for leaks. Try pushing down on the rear or pushing the front of the car and see if it makes the same noise. BTW - Are you out of warranty?
Remember, with electronic SBC, that when you are on the accelerator and you quickly depress the brake pedal (as you would in an emergency stop), the brake pedal stiffens and only slight brake pedal pressure is needed to lock up the brakes. This provides a quicker reaction time for shorter stopping distance.
Remember, with electronic SBC, that when you are on the accelerator and you quickly depress the brake pedal (as you would in an emergency stop), the brake pedal stiffens and only slight brake pedal pressure is needed to lock up the brakes. This provides a quicker reaction time for shorter stopping distance.
