In my '98 E320 (W210) I'm hearing a grinding noise from the rear when coming to a stop. The brake light does not come on.

The pads do not look worn. The rotors measured 10.5 mm. Does anyone know the spec on rotor thickness?

Should I just try replacing the pads even though the sensors do not indicate they are worn?

Thanks in advance.

I'm not familiar with the 98 model. Does it have wear sensors on the rear? Mine don't, and even if you do they are not foolproof. What do the rotor surfaces look like? Brake pad wear light comes on at 2.5 mm thickness. Have you checked the thickness of all four rear pads? If they check okay you may need to remove them and check for grit. Sometimes small pebbles can get lodged somewhere on the wear surface.

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95 E320 Cabriolet, 159K

The emergency brakes on that model are in the rear and seperate from the brake pads. Mine came apart and was making noise and even binded up when backing up.

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98 E430(sport), 99 ML 320 (sold) , 05 C 230(sport) Mark

Yes, there are wear sensors on the rear bakes. They do not indicate worn brakes. The pads are worn evenly and have more than 2.5 mm. The rear rotors have a little scoring.

So if the pads aren't worn, is dirt a likely culprit? Should I go ahead and replace the pads anyway?

Is 10.5 mm within spec for the rear rotors?

Thanks

cerbomark,

Thanks for the reply. I'm not familiar with the parking brake on this model and I didn't find any details searching the discussion group.

Can you provide any details on parking brake adjustment/replacement?

P.S. - I'm jealous of your E430 Sport. That's what I wanted, but my wife fell in love with our E320 becuase it was blue.

Benzthere,
Does your '98 E320 have rear brake sensors on both sides? Mine only has a sensor on the right side.
I'm sorry I can't offer any suggestions to solve your noise issue, other than it might be caused by non OE quality pads. I'm also curious what the minimum rotor thickness is for the '98 E320.
Rex

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1998 Mercedes E320 110+k
2000 Chrysler Town & Country Limited 85+k
1972 Ford Mustang 180+k
1988 Ford Tbird Sport (gave to nephew at 245k...still going at 270+k)
1983 Ford Tbird (traded at 135k)

There is a emergency brake set up that is not part of the rear pads like on most cars. I don t know enough about it because the dealer found the problem and replaced But the pad de laminated it self from the plate on the e brake causing it to rub. I ll bet if it happens once it happens 1000 times.
PS My e430 is for sale. Mint, low miles w warrenty. It will be in Jan/ Feb star mag...

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98 E430(sport), 99 ML 320 (sold) , 05 C 230(sport) Mark

I had a simular problem with my 2000 ML430 rear pads making grinding noise no warning light at approx 28,000 miles. Problem was the light was not working and the pads needed to be replaced. This German Engineering is just overwhelming.

If the pads and rotors are fine, why replace them? All my MB's have made noises from the brakes even when in good shape, depending on the amount of dust/dirt/etc. is present.

Have 'em checked (front too, to be safe) and if they're not worn out, drive the car. The rear pads on my C230 have about 1/3 left and are quite noisy now (winter means road grime, etc.) but I'm certainly not going to chuck good pads in an effort to make them quiet.

ASR/ESP equipped cars can be very hard on the rear pads if you use the system lots, and they have pad sensors (one or two?) in the rear.

Also, for those that need new pads at low miles despite no noise or warning light, if it's not you checking the pad thickness, ask to see the pads in the caliper before authorizing replacement. One of my local dealers told me my rear pads and rotors were shot at 60K. The pads were down to about 15%, but the rotors had lots left. The mechanic stated that they used a more conservative measurement than MB "to be safe." BS. I changed the pads and kept the rotors in. At 153K the rear rotors are still within spec and the second set of pads has about 1/3 remaining. It seems some dealers see pads below 50% or rotors below 50% and immediately call to tell you they're shot.

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John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

I havn't done the rear brakes on my 98 E320 but have done the front brakes.

Looking at the rear brakes I also have only one sensor on the right side - no wear sensors on the left.

Look at the rear rotor - the minimum thickness is usually stamped on the rotor.

Keep in mind that the minimum rotor thickness is based after turning the rotors.

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Ray
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles

The absolute minimum thickness should be 8.3mm.The minimum thickness when replacing pads is 8.8mm as per MB specs. The parking brakes use shoes inside the rear rotors, usually when the parking brake shoes come apart they will make noise whenever the car is moving not just when the brakes are applied.

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Mercedes Benz Master Tech - Retired

Originally I checked only the right rear because I thought that was were the grinding was coming from. The right side was OK, and as mbRex stated, the wear sensors are only on the right side.

(Ooops, continued...)

The problem was with the left side. The outside pad was 5mm thick, the inside pad was 0 mm thick! It was GONE. Either the pad separated from the backing or the inside wore much faster. Is uneven wear normal or do I have a caliper problem?

The inside of the rotor is scored pretty good. If the rotors shouldn't be turned, should I replace it or just let it go? It's plenty thick and not warped.

All, thanks for the advice.

I replaced the rear brake pads and everything seems OK now. I'm going to keep an eye on how evenly the pads wear.

If I have more problems I guess I'll asking for advice on rebuilding the calipers.

Thanks for the help.

If it was my car I would have had the rotor turned or replaced. Brake pads are meant to contact a flat surface - I don't consider a scored rotor a flat surface.

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Ray
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles