A small bit to consider. While I can't speak to the car in question, USA and ROW model launches / model years don't always coincide.

As an example, the 90's era R129 was never offered in the US as a SL280 , the ROW 300SL was a 12 valve and after 97 the SL320 with an inline 6 was dropped in the US but continued on as a V6 for the ROW.

(EDIT: this is a 1985 300D. I'm genuinely unsure what that confusion was about regarding model/year, and it was stated in the first post.)

Hey all,

I did not realize this thread was receiving replies. My fault per technicalities!
Updates..

I brought the car in and they took a look and also put in the correct pins. So, i suppose the pin issue is settled. Assuming they got it right the second time. And assuming the first pins didn't cause some kind of related damage during 250 miles of driving. Yeesh.
It didn't change the rumbling/vibrating issue though.

However, the brake indicator light is out now, and that was also my fault sort of. I hadn't realized that the parking break pedal itself could be causing it. I had pulled the brake release knob many times just to be sure, but hadn't thought of lifting the pedal itself up some. That did the trick. So the pedal needs a new spring. But that's no big deal for now. It stays up once you pull it up. It's a tiny amount it was down.

The issue of rumbling could be bearings. I've done some research. After looking around, at first i was concerned it could be the lower ball joint, which i understand is a lot of work to replace. But i've been thinking/hoping maybe it's the bearings, based on symptoms and the type sound/vibration.

Also, I didn't realize that packing the bearings was part of replacing rotors. But either way, I didn't have either of the front wheel rotors replaced. Just the pads. I did have one of the back rotors replaced.

But now i'm having the remaining three rotors replaced so that i can rest a little easier going forward. It makes sense to just stomach it now. This is the only task i'm shopping out. The brakes are still squeeking a lot after 250 miles of fresh pads. I'll need to break the pads down a little with the new rotors now but i'm hoping after that it'll be smooth sailing.

The interesting news is that i do have a complete replacement wheel in the trunk. Not just a typical spare. So, i guess i could either A) have them put on the trunk wheel and see if that stops the issue, or B) have them rotate the tires so that the problem wheel is in back where less turning is involved, or C) have them check the bearing situation in the problem wheel.

I'm leaning towards A as a starting point. I could have them pop on the wheel when i drop it off and take it around the block once. If it solves the issue, it took very little time and cost to do it.

Does this sound like a good approach?

They are not a hobbyist shop. They do seem to have organizational/tidyness issues. But they are committed enough to make things right after this mistake and of course did the pin replacement and general double check for free. I'll just stick out this brake/wheel project and go elsewhere if/when i need different things in the future.

I don't think changing the wheel will solve your issue. Not if the tires and wheels are all the same size and not rubbing on the wheel well. I find it a little hard to believe that a professional brake shop would send you out the door with a bad wheel bearing. Of course, I wouldn't expect them to send you home with the wrong pins in the caliper springs either. Replacing the front rotors involves removing the bearings, cleaning them, repacking with grease, then nstalling with the proper torque pre-load. People who aren't particular about specifics will end up costing you money.
https://www.startekinfo.com/StarTek/outside/12265/?requestedDocId=12265

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1982 300CD Petrol/Black Leather

So i have the same shop installing new rotors on the other three wheels. I know this was all a DIY capable project but just this first time i wanted to hire it out and also wanted the same people to complete the task.

Here is a pic of the one wheel that had both the pad and the rotor replaced at the same time. There is a groove in it already, after about a week or so of driving.

Is this a bad sign of anything? Or is it just inherent that the wear will be imperfect due to dirt and debris getting in between pad and rotor..?




I have been continuing to try to suss out the cause of the vibration when turning right. I spoke with the shop and when they install the new front rotors they are going to pay special attention to repacking those bearings.

I suppose it could be that repacking the bearings somehow clears things up. But i'm assuming i am going to need to keep investigating it. If it doesn't get resolved soon I may take the vehicle in for a diagnostic at a better shop.

Doesn't seem right to me. Shouldn't be a groove there. Pull the pads to see what is causing it. ONly takes a minute or two.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Well, that's not good. There's obviously something wrong. That might need to get resurfaced. Good thing is that it's the rear and easily removed. The shop should be able to do that for free on a disc they installed last week. See what's going on with your caliper/pads. See a screwdriver handle sticking out anywhere? I've heard of doctors leaving clamps inside patients.

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1982 300CD Petrol/Black Leather

What is the symptom/result i would eventually notice if i didn't get it resurfaced?

The groove would not bother me. Its small and insignificant.

I'd suspect bad wheel bearings causing the rumble. Sometimes they are hard to trace. Fronts are fairly easy to change and probably should have been done when the work was done on that end. Rears are a bit more work and sometimes tricky to diagnose.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

"...a subtle rubbing sound in the front left wheel, when turning right and not while braking. This was not the wheel that needed a new rotor. And this rubbing had not been there previously."

Can new brake pads cause worn bearings to start making noise? Heck of a coincidence if their time to give up the ghost was exactly when you brought it in to the shop.

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1982 300CD Petrol/Black Leather

My attitude about the groove also. However, what put the groove in there is a concern. With new rotor and new pads there shouldn't be anything there to cause such intense localized pressure.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I'm going to ask them to inspect the groove with me in person. I mentioned it to them when i took this pic (while they were installing the other three rotors but for some reason had this wheel off too) but i don't know if they actually considered it after i left and let them do the work.
I can conclude that i will not be doing anything going forward with them once this matter resolved. I gave them a lot of faith but multiple times now they have disappointed me in their attention to detail. Pretty big mistakes too.
So i'd prefer to just buy a car jack and do the front bearing work myself some time soon. Makes me wish i'd done all the brake work myself. But hey, at least i didn't have to do it. I guess!

I am also changing the power steering fluid today. It's very old looking and dark and a little low. I have another thread going Muffled "Chewbacca" rumble sound when turning right..? and it's been suggested this could be a cause of the rumble. Might as well address it and see.

Well i called the shop owner and he said he did look at the groove and determined that it was caused by, to my understanding, a protective metallic type coating that is on new pads and wears away after a short bit of time. He said something like "they don't use aspestos anymore" and they use some kind of metallic stuff, and this is what caused this and it won't continue to happen. The groove won't get deeper.

Sound normal?

Also i am hopping over to a new thread to focus on sorting the rumbling issue as this could be ongoing and very unrelated to the brake issue of this present thread. Muffled "Chewbacca" rumble sound when turning right..?

Well, some pads do have little metal bits in them. They glitter a little when you look at them in the sun. And new rotors come with a light coating of oil that needs to be cleaned off with brake cleaner. I know that new brakes like to be bed-in, but I haven't heard of any metallic coating applied to new pads. What would the purpose of that be?

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1982 300CD Petrol/Black Leather

Total BS in my view. No metallic coating will cause a narrow groove like that. There has to be something very hard wedged between the pad and the rotor to cause that problem unless the groove was there at installation of the rotor.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

i took the owner for a 5 minute spin and it's all very frustrating. hard to not be pretty pissy but i guess i have to tough it out until it's resolved.
brakes are squeeling a ton now. i guess i've driven around 50-75 miles or so since the last work was done. the first round was all pads and one rotor, the second round a week later was the other three rotors.
so, 50-75 miles or so since everything is "fresh". and they're increasingly squeeling now. Just as loud as when i had old rotors and pads.
He says he may have put on pads that are too hard and are built to last longer and that we may need to put all new pads on.
He also insists the groove in the rotor is a mystery but it could be caused by something random like a piece of rust.
But he won't set the time to look at the car until saturday, three days from now. And at that time he will then decide what pads to order. So i'm looking at waiting an extra week or so of driving around on an expensive noisy and potentially damaged brake job.
This forum isn't a place to just vent but damn i sure wish he would have the kind of business practice that i hold myself which is that if a job you performed is faulty you at least make a little sacrifice and put maybe squeeze 30 minutes of attention into this immediately. Get the car up on the lift and take a wheel off for a peek. Not that hard.