HELP!!! Something has finally broken down! - Page 6 - PeachParts Mercedes-Benz Forum

spark3542 · #76 03-05-2007, 07:52 AM

Use the $8 sway bar links.

What was causing the noise? I see lots of entries about brake pads and brake bleeding, but nothing about the noise and drag?

As near as I can tell, you didn't have any problems with the brakes, so changing fluid and pads and calipers is well and good for the longevity of the car, but have you fixed the reason the car is up on jackstands?

Buying rebuilt calipers is the way to go. It is basically swapping your for the last guy's calipers that just got rebuilt. You'll pay a core charge if you don't return your calipers when you buy the rebuilt one. That's the way it works. Finding a rebuilder just to make sure you get your calipers back doesn't really make a difference.

I wouldn't try to work the caliper free, or try to "rebuild" it myself by taking it apart and cleaning it. Just get a rebuilt one.

rino · #77 03-05-2007, 08:16 AM

Quote:

Originally Posted by spark3542

Use the $8 sway bar links.

What makes you sure it's the appropriate thing? Have you done it yourself? The two links are different, one (the original) is longer than the other, and the way they attach at both ends is totally different... I just want to make sure you are right (I hope you are)

Quote:

What was causing the noise? I see lots of entries about brake pads and brake bleeding, but nothing about the noise and drag?

Well, I don't know yet for certain and there have been many different guesses from the forum, also in other threads about this problem, ranging from bad parking brake shoes (dragging), bad calipers (stuck), etc.

I just discovered that the rear rotors are at a tilted angle with the calipers (wearing out the pads exactly at that angle on both rear sides)... for details please see:

DIY tune-up for the original MB calipers...

Quote:

As near as I can tell, you didn't have any problems with the brakes, so changing fluid and pads and calipers is well and good for the longevity of the car, but have you fixed the reason the car is up on jackstands?

I think the problem is with the brakes (the rotors at a tilted angle are almost touching the frame at some point, and it is conceivable to me that when the car moves and turns they do so). The fact that I have a broken sway bar link on one side (the side where the strongest noise comes from) might have something to do with the tilted rotor/caliper angle... I am trying to find out. It seems that the matter at hand is a little more complicated than we all initially thought...

Quote:

Buying rebuilt calipers is the way to go. It is basically swapping your for the last guy's calipers that just got rebuilt. You'll pay a core charge if you don't return your calipers when you buy the rebuilt one. That's the way it works. Finding a rebuilder just to make sure you get your calipers back doesn't really make a difference.

I wouldn't try to work the caliper free, or try to "rebuild" it myself by taking it apart and cleaning it. Just get a rebuilt one.

The point here though is to also understand if I need to change calipers... since the problem, as I explained above, might not reside there.
We have gone from a hypothesis to another and to yet another here over the past few days... I hope this is it and that I can finally get to drive my car again soon...

Thanks,
Rino

spark3542 · #78 03-05-2007, 08:56 AM

The point, and therefore value, of a forum is to help in an "unknown" area to identify what's important and what isn't.

Sway bars are not important. Don't take that out of context. You want to have sway bars on your car, it makes a significant difference in handling. But you don't need them to drive. To repair them, you can use a piece of wood and two carriage bolts and it performs just as well as factory. That's what I mean by not important. Don't dwell on whether you made the right sway bar link decision.

Brakes are important. Unless you have a clean, well lit, and properly tooled environment, I wouldn't risk rebuilding a caliper myself. Buying a rebuilt is just too logical. Doing something poorly during the caliper rebuild can have much worse effects than putting the sway bar link in wrong.

"rotor tilted" is confusing to me. Unless the whole bearing assembly is tilted with reference to the backing plate, then your wheel would wobble driving down the road. If wear is uneven on the rotor or the pads, then I would replace the rotors, pads, and calipers and be done with it. As someone previously stated, worn parking brake shoes are no big deal, because they are not designed to do any functional braking, just keeping the car still while parked.

You should be able to rotate the rotor by hand (with parking brake released), but it will take some work. It won't spin without resistance. This is normal. If both tires are in the air, it should rotate the opposite tire in the opposite direction. If the transmission is in neutral, it may instead spin the driveshaft. If it takes "tools" or unusual force to rotate a rotor, then something is wrong. If there's is significant metal-on-metal sound, then something is wrong.

Find the root cause, but don't overthink the problem. It usually is fairly simple, and it's not often that two things break at the same time. Keep that in mind as you troubleshoot.

Surf-n-Turf · #79 03-05-2007, 10:15 AM

Rino my fine friend from LA. I'll put one of the "common links" on my '79 240D tonite with pictures and so you can see. I know you want to save money, we all do. But brakes, in my opinion, are not the place to cheapen up. How much will it cost if they completely fail? I'd be willing to bet a whole lot more than $300. Get rebuilds and be done with it if that turns out to be the problem.

Stevo · #80 03-05-2007, 10:44 AM

I would buy "loaded", (complete with pads installed) rebuilt callipers. I get the less expensive pads as they wear out faster than the better ones but your rotors last longer.

vstech · #81 03-05-2007, 11:20 AM

I also am confused to the "tilted" rotor... assuming the pad and the rotor are in plane, the face of the rotor should be perpendicular with the earth... Plumb if you will. and it should be parallel with the frame of the car. if you can describe what is "tilted" it may help us figure out what is wrong.
looking at the rotor from the back of the car, what is tilted? the outer edge to the inner edge of the braking surface? that points to bad rotor and caliper both.
give some more details.
John

rino · #82 03-05-2007, 03:00 PM

Quote:

Originally Posted by spark3542

The point, and therefore value, of a forum is to help in an "unknown" area to identify what's important and what isn't.

Sway bars are not important. Don't take that out of context. You want to have sway bars on your car, it makes a significant difference in handling. But you don't need them to drive. To repair them, you can use a piece of wood and two carriage bolts and it performs just as well as factory. That's what I mean by not important. Don't dwell on whether you made the right sway bar link decision.

OK, thanks for telling me... I did not know that until now. I thought they were really important things, actually I came to believe that they might be responsible for that noise I was experiencing, and the strange wear pattern in my brake pads. You see, I'm a starting DIYer, and nobody told me this before. How should I have known?

Quote:

Brakes are important. Unless you have a clean, well lit, and properly tooled environment, I wouldn't risk rebuilding a caliper myself. Buying a rebuilt is just too logical. Doing something poorly during the caliper rebuild can have much worse effects than putting the sway bar link in wrong.

OK, I am with you all the way.

Quote:

"rotor tilted" is confusing to me. Unless the whole bearing assembly is tilted with reference to the backing plate, then your wheel would wobble driving down the road. If wear is uneven on the rotor or the pads, then I would replace the rotors, pads, and calipers and be done with it. As someone previously stated, worn parking brake shoes are no big deal, because they are not designed to do any functional braking, just keeping the car still while parked.

Let me explain: I noticed the same exact wear pattern on both RL and RR brake pads. For instance, I don't remember exactly off my mind now, but something like this: RR = inside one worn out prevalently on the lower side, external one worn out mostly on the upper side; RL = inside one worn out prevalently on the upper side, external one worn out mostly on the lower side. What can cause this? - I thought to myself - and it hit me that it could be rotors tilted somehow to one side... I didn't say it was so, but asked "could it be so?" I don't think the wheels wobbled driving down the road... The wear is uneven in the pads, and also the rear rotors' edges seem dangerously close to the frames in which they are set at both the upper and bottom areas. What do you make of this? What could be causing it on both rotors/calipers/pads, the same pattern on both sides of the vehicle... this is what I am trying to understand before going out and start buying stuff which might not be what I need to fix the problem at hand...

Quote:

You should be able to rotate the rotor by hand (with parking brake released), but it will take some work. It won't spin without resistance. This is normal. If both tires are in the air, it should rotate the opposite tire in the opposite direction. If the transmission is in neutral, it may instead spin the driveshaft. If it takes "tools" or unusual force to rotate a rotor, then something is wrong. If there's is significant metal-on-metal sound, then something is wrong.

I am able to rotate the wheels (I tried only with tires installed) in both directions, and there is much more friction involved in the rear ones than the front wheels. The rear ones don't spin freely, but they rotate with not too much of an effort on my part. I did not check what happened to the opposite tire when rotating the one at my side (how could I, being by myself?) I tried only with the transmission in neutral. Yes, there is a metal-on-metal sound, on both sides but more on the right wheel, and I am trying to identify what that may be...

Quote:

Find the root cause, but don't overthink the problem. It usually is fairly simple, and it's not often that two things break at the same time. Keep that in mind as you troubleshoot.

You see, you have expressed my thinking exactly... if it were calipers, how could two calipers start acting out at the same time... That wear pattern also on both sides, what does it tell us, fairly simply? Please advise what I need to troubleshoot at this point?

I mean, di I go ahead and change everything (rotors, calipers, pads)? Or start with the pads and see how that goes? How about that strange pad wear pattern?

Thank you so much,
Rino

rino · #83 03-05-2007, 03:06 PM

Quote:

Originally Posted by Surf-n-Turf

Rino my fine friend from LA. I'll put one of the "common links" on my '79 240D tonite with pictures and so you can see. I know you want to save money, we all do. But brakes, in my opinion, are not the place to cheapen up. How much will it cost if they completely fail? I'd be willing to bet a whole lot more than $300. Get rebuilds and be done with it if that turns out to be the problem.

My fine friend Mark, I don't want you to go to the trouble of doing that. The links are already on their way, so I'll try installing them when they get here. Besides, the other Mark said that SBLs are not a big deal and won't fix the problem (I erroneously thought they might), so it's not a big deal at this point. You are right about brakes being important, but I don't even know if it is brakes anymore... Somebody said that is not likely to be the problem here. I'd appreciate someone guiding my troubleshooting (do this, now do that, etc.) so that I can pinpoint what is causing this trouble before starting to buy blindly stuff that I might not even need...

Makes sense to you?

Rino

rino · #84 03-05-2007, 03:08 PM

Quote:

Originally Posted by vstech

I also am confused to the "tilted" rotor... assuming the pad and the rotor are in plane, the face of the rotor should be perpendicular with the earth... Plumb if you will. and it should be parallel with the frame of the car. if you can describe what is "tilted" it may help us figure out what is wrong.
looking at the rotor from the back of the car, what is tilted? the outer edge to the inner edge of the braking surface? that points to bad rotor and caliper both.
give some more details.
John

John, please see my previous post where I explain it to the best of my understanding of it... I need to leave now... I'll be back tonight and check on replies...

Thanks,
Rino

spark3542 · #85 03-05-2007, 04:12 PM

Quote:

Originally Posted by rino

OK, thanks for telling me... I did not know that until now. I thought they were really important things, actually I came to believe that they might be responsible for that noise I was experiencing, and the strange wear pattern in my brake pads. You see, I'm a starting DIYer, and nobody told me this before. How should I have known?

OK, I am with you all the way.

Let me explain: I noticed the same exact wear pattern on both RL and RR brake pads. For instance, I don't remember exactly off my mind now, but something like this: RR = inside one worn out prevalently on the lower side, external one worn out mostly on the upper side; RL = inside one worn out prevalently on the upper side, external one worn out mostly on the lower side. What can cause this? - I thought to myself - and it hit me that it could be rotors tilted somehow to one side... I didn't say it was so, but asked "could it be so?" I don't think the wheels wobbled driving down the road... The wear is uneven in the pads, and also the rear rotors' edges seem dangerously close to the frames in which they are set at both the upper and bottom areas. What do you make of this? What could be causing it on both rotors/calipers/pads, the same pattern on both sides of the vehicle... this is what I am trying to understand before going out and start buying stuff which might not be what I need to fix the problem at hand...

I am able to rotate the wheels (I tried only with tires installed) in both directions, and there is much more friction involved in the rear ones than the front wheels. The rear ones don't spin freely, but they rotate with not too much of an effort on my part. I did not check what happened to the opposite tire when rotating the one at my side (how could I, being by myself?) I tried only with the transmission in neutral. Yes, there is a metal-on-metal sound, on both sides but more on the right wheel, and I am trying to identify what that may be...

You see, you have expressed my thinking exactly... if it were calipers, how could two calipers start acting out at the same time... That wear pattern also on both sides, what does it tell us, fairly simply? Please advise what I need to troubleshoot at this point?

I mean, di I go ahead and change everything (rotors, calipers, pads)? Or start with the pads and see how that goes? How about that strange pad wear pattern?

Thank you so much,
Rino

Back to original issue...serious noise and drag...able to limp home but must fix the problem before it's driven again.

From that description, the problem is not caused by sway bar link. It is not caused by uneven brake pad wear. It is not caused by worn rotors. I doubt your rotors are "tilted". It is not caused by old brake fluid.

Something mechanical changed and should be easily diagnosed. I still support my previous post that a nut from the sway bar link bushing fell inside the parking brake shoe area and is binding against the back of the rotor in that area.

Find the source of the noise and drag. Fix that. Once the caliper is removed from the backing plate (two bolts, I believe they're 18mm), the rotor should come off easily. If it doesn't want to come, a little PB Blaster or WD40 in the area around the center hub and a little persuasion with a rubber mallet should work. (Make sure your parking brake is released)

Then once the mechanical problem is fixed, take a look at the brakes to see if you want to address this, or reassemble as is. I recently helped a friend replace brakes on a BMW 5series, and the rotors he ordered online were incorrect. They fit on the hub, but once the caliper was bolted back on, they bound up. Upon careful inspection, the actual rotor surface was about .100" offset from the original unit. Had we continued with these rotors, they would've torqued the caliper, which would've worn the pads at an angle as you described. Not sure if this is your problem or not.

If it were my high-mileage, 20 something year old car, I would just replace the rotors, buy rebuilt calipers, and new pads. Shop around online and you can find good prices. If the total for this (I'm guessing around $300) is too steep at the moment, put it all back together the way it was, and drive it for a while until you're ready. Changing just pads, or just rotors, etc., will just frustrate you and cost you more when you have to replace them again shortly.

I'm 99% confident that the unusual wear on your pads has absolutely nothing to do with the catastrophic problem you experienced 1/2 mile from your house.

rino · #86 03-05-2007, 07:31 PM

I've come back to the forum ASAP to report this:

about an hour ago I had to stop by my house (with about half an hour idle time on my hands...) I had a flash of inspiration, went downstairs, tightened up the tires lug bolts and started driving the car around the block (just to check the status of things...)
SURPRISE, SURPRISE! The horrible noise (the one that started 1/2 mile from my residence the last day I drove the car and gave me much concern) is gone...
I drove the car for about 30 minutes. No signs of that loud metal-to-metal noise (coming from the right wheel) whatsoever!

Now can somebody explain this? The only things I did, which might have impacted whatever the problem was, were: changing the brake fluid two days ago (by the way, braking power is great) and removing and putting back the rear brake pads and shims...

Of course, there are still the minor noises which have been going on for some time now: the clunk noise, which happened only during the first four or five RIGHT turns (on right turns only) - CLUNK! CLUNK! CLUNK! CLUNK! CLUNK! about five clunks per turn - and then disappeared (as whatever was producing it warmed up, I presume) and the rumbling noise, happening unpredictably once in a while (it happened thrice during the 30-minute drive) when turning, either left or right - RUMBLE... RUMBLE... RUMBLE... RUMBLE... at each turn...
Now these don't worry me (perhaps they should) as much as the terrible one that showed up a few days ago and is now gone did, but will replacing the sway bar links stand a chance of taking care of these lesser noises, in your opinion?

Quote:

Originally Posted by spark3542

Back to original issue...serious noise and drag...able to limp home but must fix the problem before it's driven again.

From that description, the problem is not caused by sway bar link. It is not caused by uneven brake pad wear. It is not caused by worn rotors. I doubt your rotors are "tilted". It is not caused by old brake fluid.

Something mechanical changed and should be easily diagnosed. I still support my previous post that a nut from the sway bar link bushing fell inside the parking brake shoe area and is binding against the back of the rotor in that area.

OK, that's the serious noise and drag that I have just reported about, gone now.
What do you make of it? Question: how could a nut fall inside the parking brake shoe area... I couldn't even find it when I looked for it two days ago... I think it's covered and that you need to remove something to access it... but I might be wrong...

Quote:

Find the source of the noise and drag. Fix that. Once the caliper is removed from the backing plate (two bolts, I believe they're 18mm), the rotor should come off easily. If it doesn't want to come, a little PB Blaster or WD40 in the area around the center hub and a little persuasion with a rubber mallet should work. (Make sure your parking brake is released)

Then once the mechanical problem is fixed, take a look at the brakes to see if you want to address this, or reassemble as is. I recently helped a friend replace brakes on a BMW 5series, and the rotors he ordered online were incorrect. They fit on the hub, but once the caliper was bolted back on, they bound up. Upon careful inspection, the actual rotor surface was about .100" offset from the original unit. Had we continued with these rotors, they would've torqued the caliper, which would've worn the pads at an angle as you described. Not sure if this is your problem or not.

I already took a close look at the brakes two days ago, and I have described earlier what I have found. I have new pads ready (soft ones, that will show pretty quickly if the same wear pattern is going to take place) and would like to install those and see what happens. What else could be the problem, aside from what happened to your friend (given that the rotors in my car are rusty and old and I doubt they were changed in recent years), causing that sort of pad wear, in your opinion? Also, do you estimate that the very alarming noise might happen again or that it has somehow been resolved permanently?

Quote:

If it were my high-mileage, 20 something year old car, I would just replace the rotors, buy rebuilt calipers, and new pads. Shop around online and you can find good prices. If the total for this (I'm guessing around $300) is too steep at the moment, put it all back together the way it was, and drive it for a while until you're ready. Changing just pads, or just rotors, etc., will just frustrate you and cost you more when you have to replace them again shortly.

Look, I paid $14 (at pepboys) for the soft pads I am ready to install... no big deal if they go down the drain fast... but there's still a chance they'll hold longer than that... and give me an opportunity to test whether the same pattern occurs again.

Quote:

I'm 99% confident that the unusual wear on your pads has absolutely nothing to do with the catastrophic problem you experienced 1/2 mile from your house.

Well, you are right, since those pads are still installed and the catastrophic noise is gone... what makes me think that the noise was somehow originated within the rear brake area is that the only things that were done to the car since that occurrence were the brake fluid change and the extracting/re-installing of the old rear pads... aside from taking off the tires and putting them back a few times, putting the car on stands/off stands a few times...

IDEAS?

Thanks for your help,
Rino

#87 03-05-2007, 07:40 PM

FWIW, I once had a "horrible" noise from a rear wheel after rotating the tires. It turned out that one of the front rims was bent slightly, it had plenty of clearance on the front, but it rubbed the rear hub on every rotation. I removed the wheel and could see rub marks on the inside of the wheel. Your comment about tightening the lug bolts reminded me of that. Did you move any wheels around?

rino · #88 03-05-2007, 07:55 PM

Quote:

Originally Posted by Craig

FWIW, I once had a "horrible" noise from a rear wheel after rotating the tires. It turned out that one of the front rims was bent slightly, it had plenty of clearance on the front, but it rubbed the rear hub on every rotation. I removed the wheel and could see rub marks on the inside of the wheel. Your comment about tightening the lug bolts reminded me of that. Did you move any wheels around?

Never did... since buying the car two years ago.

Rino

vstech · #89 03-05-2007, 08:13 PM

ok, I see you put in pads, did you check the two 17mm bolts that hold the caliper to the spindle? the only thing I can think of that would allow the pads to wear in that pattern is the calipers pivoting as you apply pressure to them.
they should be VERY TIGHT, and the caliper should not move at all. I would pull off the wheels, and check the calipers. loosen the pads up, and try to wiggle the calipers. they should not move at all in any direction.
the horrible noise was most likely just the edge of the pads touching the rotor hat. check this, and report back.
John

rino · #90 03-06-2007, 05:21 AM

Quote:

Originally Posted by vstech

ok, I see you put in pads, did you check the two 17mm bolts that hold the caliper to the spindle? the only thing I can think of that would allow the pads to wear in that pattern is the calipers pivoting as you apply pressure to them.
they should be VERY TIGHT, and the caliper should not move at all. I would pull off the wheels, and check the calipers. loosen the pads up, and try to wiggle the calipers. they should not move at all in any direction.
the horrible noise was most likely just the edge of the pads touching the rotor hat. check this, and report back.
John

John, to avoid misunderstandings... I pulled out all the rear pads for checking, then I put back in the SAME old pads - not new ones. At the time I didn't know if I was going to replace the calipers, so I did not put in new pads, but the old ones at exactly the same angles they were before...
Thanks for pointing to possible loose calipers... I didn't check those bolts, but I will first thing as soon as I put the car up again... However, I have to say that I remember the calipers being firmly attached to the frame. I'll wait until I get the shipment with the new brake shims (the ones installed right now are in very poor shape...) and the sway bar links, then take the wheels off and do everything in one session. This is probably going to happen on Wednesday night, so you'll know by the following morning.

One question: when I pulled the old pads out a few days ago, I tried to push the calipers' pistons back for ease of reinsertion, but to no avail. I was using one of those specific tools made for this purpose that you buy at auto part stores... but it was not easy at all, since there is no place to anchor the tool for leverage in these old calipers, or to place the part of the tool supposed to push in the piston directly centered on the piston... in short, those parts within the caliper you are supposed to apply the tool on are hard to reach... Does anyone know how to make this procedure a little easier?

Thanks,
Rino