Hello, I've got a 1989 W124 300D. Well last week I redid a caliper and pads on the rear brakes. Then I discovered a warped rotor on the front driver's side. I went to take it off and the brake is completely different. I got the caliper off and the pads looked good, but the rotor is warped and I imagine it is on the other side too. First of all, how do you remove the pad with the sensor on it? I am going to replace them because I am going to resurface the rotor, it isn't terribly warped. And how do I get this rotor off? After removing the caliper there was a metal bracket in the way with a couple bolts that were horribly rusted and I could not budge them. Any help would be appreciated! I don't know why the front brakes are so much more complicated than the back.

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1984 300TD OM617 project. Rusted apart exhaust, leaking roof, bad interior. WIP
1983 300D OM617 straight piped, rusty, dented, and sketchy.
1982 300D OM617 parts car, assumed low/no compression at this point.
2005 F250 6.0L, custom tuned, stage 2 VGT, 175/30 injectors, all supporting mods. Currently parked with a smoked transmission.
Sold: 1989 grey market 300D OM603 N/A

Are these the calipers that have to swing out to clear the rotor so you can remove the pads vs the other kind that the pads are held by a couple of pins? If so, the answer is you remove a couple of bolts (10mm socket?) to release the working section of the caliper and replace the pads. IIRC you can remove one bolt and pivot the caliper out of the way. There are a couple of bigger bolts (17 or 19mm socket) holding the caliper bracket to the knuckle. Those brackets have to come off to get to the rotor. No need to mess with the bearings if you just want to replace rotors but it's worth checking the condition of the bearing grease and bearing play.

Pelican Mercedes-Benz Tech Article - Mercedes Benz Front Brake Pad Replacement - 190E, W124, W126, W201, W123

There's not much sympathy for resurfacing rotors on this forum so consider quality replacements.

Sixto
MB-less

They are not the ones with the pins. I will try to post pictures of them tomorrow. I haven't had a chance to try again yet with work, but once I do I will take some pictures. The back ones were so easy and these front brakes looked really confusing. Also, what am I going to replace other than rotors? everything looked relatively good, but the rotors. What could have caused this? I would like to replace anything faulty to avoid this. Sticky calipers perhaps?

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1984 300TD OM617 project. Rusted apart exhaust, leaking roof, bad interior. WIP
1983 300D OM617 straight piped, rusty, dented, and sketchy.
1982 300D OM617 parts car, assumed low/no compression at this point.
2005 F250 6.0L, custom tuned, stage 2 VGT, 175/30 injectors, all supporting mods. Currently parked with a smoked transmission.
Sold: 1989 grey market 300D OM603 N/A

I only know of two kinds of front calipers on a 124 - the kind in which you pull out pads after removing pins (3.2 M104 and M119) and the kind in the DIY article linked above. Are you saying you have yet another kind?

Sixto
MB-less

I agree, the DIY should cover the brakes you have. Post a pic of what's different.

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My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
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Personally I would just replace a warped rotor with an aftermarket one. They usually can be had at not much more than machining the present rotor.

Thanks for the help. I ended up replacing calipers, pads, and rotors. Still not sure how to describe them without a picture, but I do not have any pictures of them unfortunately.

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1984 300TD OM617 project. Rusted apart exhaust, leaking roof, bad interior. WIP
1983 300D OM617 straight piped, rusty, dented, and sketchy.
1982 300D OM617 parts car, assumed low/no compression at this point.
2005 F250 6.0L, custom tuned, stage 2 VGT, 175/30 injectors, all supporting mods. Currently parked with a smoked transmission.
Sold: 1989 grey market 300D OM603 N/A

Some non-turbo 124s and 4cyl gas 124s have solid front rotors but they actually use the same front calipers and the same pads.

The rotors are hard to find but they can be bought from the dealer, I think retail is around $90 each.

My 200TD and friends 230TE had these solid rotors.

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