Went to the dealership yesterday for a rough idle and check engine light issue. Turns out that there is an "open campaign" to replace some high-pressure air intake hose(s). I LOVE how they call an ordinary recall, an "open campaign". Spin spin spin.

Anywho, the SA calls and tells me that the brake pads are at 4mm front and rear, and the front discs are below spec (when asked he could not give me the measurement). I have noticed some grooving on the front discs, so am not completely surprised that the brakes might need attention.

I researched and found a post online (mbshop?) regarding specs, but wonder if anyone here can offer advice.

1. SA says that 4mm is worth about 2,500 miles front, 4,500 rear. OK?
2. What is the limit for brake pads?
3. Why hasn't the brake-wear indicator lit up yet?
4. Does anybody know the front and rear wear limits for discs? An mbshop post said 25.4 front and 8.3 rear; but I think you guys are smarter so any confirmation would be great.
5. What's a reasonable (indy shop) price to pay for front rotors, and 4 pads? This particular w203 has the cross drilled front discs.

I've been led to believe that these brakes are relatively easy to DIY, so am considering all options, etc. The one option I'm not considering is paying $975 for the dealer to do the service.

Thanks in advance.

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1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

I will answer as much as I can:

1. New pads have approximately 12mm lining on them on the front pads and 10mm on the rear pads. I can't say exactly for that car but this is based on my experience in general. So that means you have about a 3rd left. However you probably don't want to wear down to the metal. Also the worn thickness of the pads is not necessarily consistent from top to bottom, inside to ouside, front to back. They don't wear exactly evenly. So it is possible there is a spot somewhere that is less than 4mm. Anyway assuming the car has 45,000 on it and these are the original pads I would say you should have another 10,000 left on them.

2. According to Chilton (online through my public library - you can probably get the same service from you library) the limit for that car is 2mm. However there is nothing special about 2mm. Nothing bad happens until the metal hits the disc. But basically they are saying by the time you get to 2mm "you don't have much left so change them".

3. The brake wear indicator trips at 3.5mm.

4. According to Chilton the front limit is 19.4mm, rear limit 7.3mm. Haynes says it a little different. They say 20.4mm "before repair" and 19.4 "limit". For the rear they say 7.6 and 7.3 respectively. I think they mean you can turn the front down to 19.4 but if it is less than 20.4 to start with then you can't turn it.

5. I don't know. Cross drilled rotors are more expensive than regular ones. If the dealer quote was for new drilled rotors and front and rear pads and labor then it might not really be that bad. Hopefully someone else can answer this question.

As far as DIY changing the discs is a little more involved than just doing the pads. It also depends on your experience and skill level and tools. You might try just doing the rear pads first and see how that goes and then decide if you want to try the front.

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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

thank you!!!

__________________
1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

OE list prices are about $350 for the front parts & $200 for the rear.

Add 3-4 hours labor & taxes....bingo

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
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