What's Left? C280's going off a cliff
 

OK - I've had new everything put on this '97 C280 - ball joints/control arm bushings/drag link/tierod ends/tires/high speed balancing and several MB alignments. My car continues to go out of alignment (to the right, 4 times now) and shake like hell. Rotating the tires does nothing, still there. She drives like a dream out of the shop then 100 miles later pulls to the right and starts shaking again. Had new tie rod ends, rotors and new brakes put on. No Help. The only thing left is the steering damper. Mechanics say the wheel bearings are fine. What's left?? I'm lost and giving up. Someone mentioned a loose belt (?) or maybe something going on in the steering box. I dunno, but I'm pissed. Why would this car go out of alignment SO quick? I drive like grandma in this car, haven't hit any potholes, curbs or whatever. Alignment aside, the shaking is the worst. Help - anyone! Thanks

Mark E.
Ft. Lauderdale

While I know nothing of your car's model characteristics, in general the things you describe sound more like an issue with a sticking brake caliper. They can stick (probably on the right side in your case) causing the car to pull to one side. Then the heat buildup causes the disc rotors to warp - that then causes that side to not only pull from the constant friction but then shake.

Get the rotor checked on that side, and if it is warped, replace it and either repair or replace the caliper. I think they can check the rotor warp on the car with a dial gauge.

Note: I am only a amateur mechanic, and my disclaimer is that I know nothing.

:)

Ken300D

Let me state that 90% or more of most severe drivability complaints (of this type) originate in the tires.

You have a top of the line car, do you have top of the line tires?

For those who don't know how to tell which are top of the line, use my method, which I use when I don't know about the subject: buy the most expensive. Which in the case of tires is Michelin. And just like the rest of the decision buy the best Michelin. You know how to tell.

And absolutely never listen to the tire salesman as he tries to sell you a cheaper tire that he makes twice as much on. Go to tirerack's site and find your base values and which models are available for your size. Then go locally and get your best price if need be. Get the best deal but buy the best product.

Wow! I really like both answers above -- both are worth checking out.

RE: the tires, if when you have rotated them, you switched backs and fronts, and you have a bad tire on the right side, you would still get the problem. You might want to put your spare in place of one of the right side tires, and if that fixes the problem you know Steve was right.

The thing I can't figure is why, if it is tires, it would get better for a while after servicing the car and 100 miles later go lame ...

My 2 cents re: tires -- when mine need replacing, I am going to go with Nokian NRVs. These received a great review in The STAR last year. There are a number of dealers around who can ship them to a local mechanic for mounting.

767Flyer,

Do a search for tire vibration or balance. There is a lengthy thread on the subject that describes a machine used at better tire sales and service facilities. I think it is a Hunter 3000GP or something. Anyway, it is apparently able to distinguish tire and wheel problems from suspension and steering system issues. Finding a place where this machine is used near you is something the manufacturer can ususally provide some assistance.

The main reason I use Michelin tires exclusively is quality and service. The added cost ends up being worth it, and I usually buy them from Tire Rack and have them installed locally. The manufacturing methods for tires sold in the European market where speed ratings are taken seriously (TUV biannual inspections in Germany look to match speed rating to car capability. A car that will go 130 mph cannot leave the inspection site under its own power with tires that are not rated accordingly) are more exacting than those used for tires only sold in markets where speed ratings are disregarded by government regulating agencies.

So, get an "H" or higher rated tire ("V" or "Z" if your car is capable of speeds over 130 mph) and choose one that will meet your other needs. I live in a place with 4 seasons, so I get the Pilot XGT series for 4 seasons and I do well in all but blizzard conditions. Some cars that means a "H4" model and others it is a "V4" choice.

One of the telltale visual features of a tire made using the more precise manufacturing techniques is evidence of a multiple segment mold. You will see slight flashing fins in the radial direction on the sidewall and across the tread on the new tire. The more, generally, the more precise the concentricity of the construction, and therefore the longer the tire will stay balanced and round.

Good luck and I hope this helps. Jim

Thanks for the responses guys. Yes, I have used the Hunter GSP (?) 7000 machine, and I can tell when it it works. I guess after dealing with this issue for a year or more now, I've been in "tune" with every little vibration that starts or stops - after all this is a Mercedes! :) The tire store down here, using the latest Hunter gadget, tells me that the tires and wheels are ok. I have Continental Ecotouring, about 5000k on them. Would a bad tire cause the car to go out of alignment? I have had all 4 tires in all four spots on the car, several times. No help.

Also I forgot to mention in my original post - at about 38,000 miles I had new rotors and brakes put on. The car had to have another new set of ROTORS and brakes put on at 48000 miles. The pads yes, I could kind of understand, but new rotors after 10000k miles? Like I said, I drive like a weenie. Since the pull and vibration always coincides with each other, could the realignments conceal the problem for awhile? I've been to 2 different independent shops (very good) and then finally the dealership. The same results after 2 visits apiece with these folks.

I was considering getting Michelins soon, but wanted to explore all alternatives as well. Like I said, all 4 tires (and the spare) have been rotated into each spot many times trying to diagnose this problem. THanks everyone! I will pursue the stuck caliper next!

Mark E.
Ft. Lauderdale

New rotors after 10k miles? Were they warped?

I got 90k miles out of my original rotors and only changed them because they were starting to wear a little thin. They still performed flawlessly.

When my C280 was my dad's car, it always had problems with steering vibration that was sometimes excessive. The local tire shop rebalanced the tires, and said they were good, etc, etc. It had Pirelli tires on it. I always knew what the problem was, though, the shop was lying. When I got the car, the first thing I did was put Michelin tires on it. Now it is 100% vibration-free. I think the old tires must have been defective, because they were seriously out of round. This was just my experience. Make sure the tires don't have flat spots on them before you try other parts.

Looks like a set of Michelins is in order. What do you guys reccommend - H rated or VR?

Mark

767Flyer,

Ali Al-Chalabi brings up a good point. Some tires have relatively soft tread compounds, mainly those that are skewed to provide better traction, at the expense of wear life. These tires also tend to be used by owners who think they are willing to give up ride characteristics for handling. A by-product of this is that they are often on the low end of inflation pressure to improve ride charactersistics in normal driving. Additonally these kinds of tires are susceptible to taking a set overnight in their at rest shape. Look at the tire at rest and it has a flat bottom. Initially these tires present a flat surface to the ground on every revolution, until they warm up and centrifugal force helps them go back to being round. The will vibrate as a result. The longer they sit the worse this can be.

But that does not address your pulling to one side issue. Is the pulling always to the same side?

Next time you take a drive for a dozen or more miles, when you get out check the temperature of the wheels on all four corners. Be careful as if you have a grabbing brake, that wheel might be very hot. A visual indication is if one wheel is getting dull and more rapidly aging the paint on the alloy wheel. If this is the case, you will need a new caliper or two, or you can have them "rebuilt" which means have the seals changed. When the piston to cylinder bore square shaped "O" ring gets worn there is no longer any mechanism to pull the pad away from the rotor after you release the brake pedal. As a result the pad stays in contact and heat the whole area up while you drive. The result is rapid wear of the pads and rotor on the aflicted wheel or wheels.

I am not sure the pulling and vibration are directly linked. I would suspect the tires/balancing for the vibration and the brakes for the pulling, assuming you have no bent front end or rear suspension parts. Good luck and I hope this helps. Jim

Jim and Ali - thanks - I appreciate the time taken to answer my questions. After searching the site about tires and stuff I see that Michelins (and counterparts) make a huge difference on this car. After reading your posts I suspect a brake problem is going on. The car spent 2 weeks at the dealership (waiting for the suspension expert to work on it) and aside from the ball joints and drag link they said everything else was in great shape. But the warped rotor(s) raised a red flag with me. With an unbalanced wheel you feel it within a certain speed range, correct? I noticed driving last night that the vibration occurs from about 45-80 mph and the pulling at any speed above about 20 mph. I will check out the wheel temps. ON the tire side, I've noticed that the vibration is a little worse during the daytime... it's been about 90 here in FL... and driving home from work at 4am the shaking isn't as bad, but still there. So - what would be your first inclination - go with the new tires or check out the brake calipers. SOmething tells me both. :)

Thanks gents!

Mark E.
Ft. Lauderdale

One other thing -- sounds like you're getting your tires balanced at a tire shop, not an MB dealer or MB independent mechanic? If so, they are probably using one-piece wheel weights. These have a habit of flying off the wheels. This has happened to me a number of times until I figured out I need to use official MB two-piece wheel weights. Dealers and some independents have 'em.

Might be worthwhile to look at your wheels and see if they all have visible weights -- if they're missing, it could explain why they do well for a while...

I would purchase Michelin MXV4 Plus tires. I don't think it matters whether they're H or V rated.

All MB dealers and many tire shops use the hunter gsp9700 balance machine.

It is just as effective in balancing tires as well as other machines, but is particularly useful when you have a tire that has wheel force variation issues and becomes problematic for a normal wheel balancing machine to handle.

Wheel force variation describes the situation of the sidewall of a tire that has too much variation between the soft spots and hard spots. All tires have hard spots and soft spots, but if the variation is too great, then a wobble develops at speed.

Go to the website to see a great video demonstration of this.

http://www.gsp9700.com/

Thanks for the response! Yep - the independent shop I have used has the 9700 machine. I can tell it's help with balancing. But still the shaking and pulling out of alignment after 100 miles or so is perplexing - I'll see what's up and let you guys know.

Thanks again!

Mark E.
Ft. Lauderdale

A rotor with a stuck caliper against it can warp within 100 miles easily.

Having to replace rotors after 10,000 miles also points to a stuck caliper. The shop hasn't caught it yet, they are just putting them back on after replacing what "looks" bad - the pads and rotors.

Ken300D

Thanks Ken - are there any outward signs of a stuck caliper, other than the pads and rotors? Or do the symptoms show up in such? I noticed today that both front wheels are very hot, more so the right - and my gas mileage has dropped a bunch.

Thanks

Mark E.

Nothing really is visible until you get the assembly taken apart and try pushing back the caliper piston. And then having someone lightly push the brakes and watch its action.

I'd say it is a problem most often diagnosed by the symptoms. And if the mechanic doesn't associate pulling and shaking with a stuck piston against warped rotors, they're just going to replace what they can SEE is bad.

You probably have to explain all the symptoms and also what has been done to the car so far. Then emphasize the heat, shaking and pulling to one side and tell them they need to thoroughly check the brake calipers.

Disc brakes are great when they are working like they are supposed to, but nobody seems to have found a sure-fire way to prevent stuck caliper pistons. It can happen due to light corrosion, improper manufacture, overextention and then twisting, and foreign object.

Relatively easy to test though when the brake assembly is taken apart and the mechanic takes the time to test the action of the caliper.

Ken300D

767Flyer,

If you want to find out if the caliper is causing the pads to drag, just jack the car up to get the wheel off the ground and try turning it. You can easily feel and perhaps hear a "dragging" sound.

This happened to my car once while on a long trip. The car started pulling very very badly to the right. When I stopped, I jacked the car up and found the right front wheel very hard to turn. I had found the problem!

Hope this helps. Let us know what you find.

Thanks Ted and Ken - I do appreciate it! I will jack the car up tomorrow and test 'er out. Why is it that some of the simplest causes have escaped my brain with this car? :D I guess I have been so wrapped up in the high-tech stuff with it that I have failed to see some basic car stuff going on.

Thanks again!

Mark E.
Ft. Lauderdale

On a normally functioning brake, you will hear a dragging sound, as the brakes do rub very lightly.

When you spin the tire, it will not go on spinning forever, as long as it turns relatively freely, it should be ok. Usually getting 2-3 turns out of a wheel indicates that it is ok.

The true test that I like to do is to get out on the highway drive for 10 miles or so without using the brakes and pull into the next highway rest stop at the earliest convenience. When you are slowing down, do not use the brakes, engine brake the car all the way down to below 10 mph, then use brakes to stop. It is important that you carefully engine brake the car all the way down to a walking pace. Now, you have been on the highway without any brake use and you did not use the brakes to stop the car. All brakes should now be cold and all be the same temperature. If a brake was rubbing due to a stuck caliper, that rotor will be hot (just be careful not to burn yourself).

H rated tires are fine, they are good up to a speed of 130 MPH and the C class is governed at 133MPH, so I do not think there is any need to go to V rated tires.

Also, I did not mean to automatically condemn your tires. Continental does make good tires, I just suggested to possibility of wanting to purchase Michelin tires and for you to check your tires to make sure there are no flat spots. There is no need to keep spending money on the car, unless you really want Michelin tires.

-Good luck.

Ali,

I like the diagnostic thought involved with your technique.

If you can get access to an infra red thermometer, you don't even have to go to such extremes. Last week I drove an old (1977) 450SL around the block and put it directly onto my drive-on lift. The Front right disc was320 degrees. The rear right was 280 and the other two were about 150. We rebuilt all four calipers.

Steve,

Actually, I do have an infrared thermometer that I keep in my car and I do use it to check various parameters on the car. When I do this test on my car with the thermometer every brake disc is almost exactly ambient temperature.

I initially got the thermometer because I thought it would have a few uses on the car. Now, there seems to be countless uses for it. For me, I think it was money well spent.

A couple of years ago, on my 325e bimmer, following a brake pad change, the caliper was rubbing so hard that after 1 mile of driving I could smell the brake burning smell from inside the car. Needless to say, the car pulled very heavily, and all was well after a caliper replacement.

Ali - I will try it out. now I have a dumb question - could a bad tire(s) cause a car to go out of alignment? Shaking I understand, but could enough wobble pull the alignment out? Just trying to eliminate stuff before I trek back to the shop. Also, you recommend rebuilt calipers instead of new ones? Do they last as long? I'm tired of the car being in the shop more than I drive it! :p

Thanks!

767Flyer

sounds like brakes, get on the highway cruise for a couple of miles, stay off brakes, then coast to the side shoulder, stop with emergency brake at around 10mph or less, then feel wheels.

What is your brake fluid change schedule since new? every two years?

767Flyer,

The vibration you have described should have no effect on alignment, however, a badly wearing tire due to unbalance or other vibration could affect the straight line performance of the car. Overall, I suspect you have a sticking caliper and I would address that as the most likely cause/ possiblility. Other, at this point seemingly less probable sources of the problem can be checked once this one has been definitively eliminated. Jim

OK guys thanks - I will run a few "tests" and check it out. I do recall my mechanic telling me there was excess wear on the front tires (new, about 2000 miles on them and freshly rotated), which I thought was strange considering my driving habits.

I will let you guys know.

Cheers,

Mark E.
767Flyer
Ft. Lauderdale

Well, I did the drive 10 miles, no brakes, coast to a stop test. The brakes were completely cool. Nothing! So I guess no stuck caliper. So it is sounding more like tires. In fact, each day the shaking gets worse and worse, and gas milage is starting to suck big time. One last question - what else in the suspension, if anything could be a culprit? When you have new rotors/brakes put on, is it customary to check the wheel bearings? How about shocks?

Thanks,

Mark E.
Ft. Lauderdale

I still wouldn't dismiss a binding brake on the basis of the 'coast to a stop' test. It could only start binding after a firm application or some heat has built up. I would also consider the flexible brake hose, even if it appears sound from the outside. My brother replaced a front caliper twice on his Alfa Romeo before realising that the flexible hose had collapsed internally - you could push brake fluid through it but it wouldn't let it return. Best of luck tracking down this problem!

Were you shaking and pulling to the right during this 10-mile drive?

Ken300D

Well everyone - do I feel like a schmuck. Today I finally said what the hell - I went and bought some Michelins. Guess what? Problem solved. After all I've put you poor guys through:rolleyes: Geesh. Sorry! Anyway, I learned a lesson here. I'm just really surprised that tires with only 10k on them would give me fits. And I just bought Continentals for my other C280 - and the ride sucks on it too. I was amazed at the ride; smooth as silk, no bone jarring over bumps, and the car is responsive again. Wow. Anyway, thanks for all your help, I do appreciate it! I should have listened to the masters: Steve, et. al thanks.

Phew - I feel better now - the car feels like a benz again.

Mark E.
Ft. Lauderdale

Excellent! Many of us have learned from your experience.

I'm staying with Michelin for sure. It seems that news story about a majority of current tires would fail more rigid standards has a lot of truth in it.

Firestones have been bad since the 70s - never understood why people kept buying those.....

Ken300D

Good to hear your problem was solved.

On my car, I had the same thing where Michelin MXV4 made the car smooth as silk. They now have 22k miles on them and still look brand new.

Guess what - IT'S BACK! I can't figure this out. One day after new tires, car drives awesome. Then, within 24 hours the shaking is back. But, this time the pulling is gone. Now just shaking. I'm wondering if the dealership missed something when putting my new suspension components in. What's different this time with the shaking is it occurs after the car has been run for about 20 minutes. I drove it late last night, and after about 20 minutes of driving the shaking started. This morning it drove great until (I'm guessing here) about 20 mintues into the drive. Why would I feel shaking in the gas pedal now? Now I'm thinking maybe brakes again. Anybody dare take a jab at this again? Is there anything driveshaft related like a support or something. When you guys get sick of me just boot me off the forum! Ultimately, (when I get this fixed - and I will get it solved) maybe my experience will educate others on here on what to do and not to do.

Thanks,
mark e.
ft. lauderdale

Engine mounts?

Flex Disk?

Exorcism?:D

Engine mounts were replaced about 9 months ago - that helped solve an overall car vibration, but this is in the steering wheel, brake and gas pedal. The dealership tells me that the felx disks are fine. So I dunno

Mark E.
Ft. Lauderdale

Have you checked your tie rod ends?

Worn out bushings can cause a tire wobble, and probably you would feel it in your steering wheel. Makes sense as the tie rods are what actually turn the wheels.

Maybe you have more than one problem. Have you checked your transmission and rear end mounts?

Thanks Paul - when I took it to the dealer they told me the tie rod ends were fine. Perhaps it is something in the rear of the car. In any event it's going back to the shop tomorrow. Unfortunately my independent has given up. I love the car so much that's why I'm being so persistent. So we'll see what's next. My gut tells me it's still in the front end somewhere. I've been searching through posts and have found a few indentical conditions that others have, but no luck on the fix.

Thanks

Mark E.

Is your independent shop a Mercedes specialist?

Does this mean that you will now take it to the dealer?

I hope they find something. It has to be something very wrong with your suspension, like something has disconnected.

Good luck.

Yeah, my independent is a MB and BMW guy. Most of his mechanics came from the two MB dealerships around here in south FL. He's been great, but has referred me to the dealership. I tend to agree - something is loose in the front end.

Mark E.

Well to help add to the empowering of others in learning about their fine MB automobiles, I will post the conclusion of this 9 month vibration problem! :)

Turns out the mechanics loosened and then re-tightened all components that support the driveshaft, and this solved my vibration problem. The flex disk(s) and other support stuff was fine - they narrowed it down to something in the driveshaft, not the front end. Since everything was in good shape, the last ditch effort was to retighten everything, and that was it. The car drives like a dream now. I wish I had known this about $2000 bucks ago, but the problem puzzled several top-notch mechanics. Thanks again to everyone on here for your help. I certainly hope others can learn a bit from these posts. I sure did!

Mark E.
Ft. Lauderdale, FL

Congratulations Mark,

It is good to know that you have found the solution to that horrible problem. Evidently you didn't waste your money on the tires, however, because it doesn't seem likely that the driveshaft could have caused the pulling to the right problem. So all of that $2000 was not wasted.

Thanks for letting us know of the outcome. Now, enjoy!!!

I suspect the fix is simpler than you think. The car is fine for a while after being in the shop. It pulls after being driven for a while. Vibration and pulling are most probably from a caliper that is not releasing fully on the front right. The fact that the car is fine for a while indicates that the caliper itself is likely not to blame. I would try the simplest fix first. Try bleeding the brakes with fresh fluid. The age of the car and the fact that most people never change their fluid until they have a brake component replaced suggests either a small amount of air in the line that is expanding as the system warms (least likely) or alternatively a small amount of water that is boiling causing a small vapour lock in the line (my money is on this one). In any case, try this first, as it is dirt cheap. Let me know how you make out.
Those who suggested a warped rotor could be right as a result of the dragging on that corner. That is easy to check when you have that wheel off for bleeding.

Eeep. I didn't read the whole thread. Any thought as to the reason for the pulling to the right?

Thanks for your reply - guess what folks? The problem is back. I've talked with Steve B. about it (thanks Steve), and I'm going to follow a few more angles to this. One constant - when the car goes in the shop and they rotate/align the car, and I get it back, it drives great - for about a day or two. Then the same problem occurs. Steering goes sloppy, and wheel shakes. It hasn't mattered what wheel is where, or how many tires I've tried (3 sets). Steve has suggested trying out new front shocks...

When I got the car out of the dealership, it drove smooth and cushy. Then, as usual, the car went bad. I know I've worn you guys out with this post. I've worn my mechanics out too. But my attitude is that I've spent close to $3500.00 trying to get it nailed down - and various mechanics have ultimately blown me off (politely, of course). The problem isn't constant, and of course the shop foreman at MB could not duplicate - 2 times. I know how my car is supposed to drive; I'm sure all of you guys know when your car is driving "right" or not? Of course you do. Not to sound arrogant, but the Boeings I "drive" at work are obviously far more complicated than my car, yet they have a 99% + dispatch reliability. Why is it so hard to get someone to take the time and figure out whats wrong with my car? I don't have time - that's why I take it in and let professionals do it. I guess. All of you on the forum have been fantastic, and again a special thanks goes to Steve B. who has taken his personal time to answer my emails - he doesn't have to, but he does. Great guy!

Anyway, thanks for letting me vent. Again, in the interest of edu-ma-cation, I will let you all know what's next. I dunno at this point.

Mark E.
Ft. Lauderdale

Well, everyone here knows I'm cheap, lazy and stubborn.

With respect to the stubborn part, I still think its the brake caliper sticking on the side that's pulling, combined with a warped rotor.

Rotor warpage is easy to check with a dial runout gauge, either on your own or at a brake shop. If you keep warping rotors - you have a bad / sticky caliper.

Ken300D

Piotr
 

hmmm, something sounds familiar. just recently I replaced both front struts in my 190 d. my sister's boyfriend helped me, and because he never drove a MB, I let him take it for a spin. When he came back, he asked if the car always takes so much effort to keep in straight line. After driving it myself, I could not believe how much out of alignment it got. The car was trying to go left and right all over the road. So I went to the alignment specialist. Guess what? alignment was fine. So the next thing was to get two new tires (yes, from tire rack). Because after driving for 20 years I firmly believe that Michelins are the most overrated and overpriced tires ever offered for sale in the USofA, I bought a pair of Yokohamas (same performance as compatible Michelins at 1/2 price). Problem solved !!!! car drove like a charm. For a month. And then the old problem returned. Front end just felt loose. Two separate mechs went over the car and said that front/rear suspension was just fine. Now, two month later, its still a little loose, but driveable.

As for your problem, I vote for the intermittent caliper problem-sticking but only occasionally and after your break fluid gets hot.

By the way, don't get sucked into the "more expensive is better" trap. essentially, all major brands in the "all season, high performance, and touring" categories deliver the same performance. the differences are so small, that have to be measured with a stopwatch on the track under controlled conditions. I guarantee, that when driving the same car, nobody of the above could distinguish between Michelins, Dunlops, Yokohama mamas, or Bridgestones (I agree that Firestone is BAD).

Ok, now come and tell me how I'm wrong and that You definitely CAn tell the diff. Right!

You bet ya! If not now, eventually. Making such a statement about tires is similar to saying all cars are alike.

I've approached this question professionally for near 30 years. If you can't tell the difference, you either aren't sensitive or don't pay attention. If you had thousands of case studies as I have you will see that Michelins stay at the good performance they come with at least twice as long as any other tire. For many the performance difference is immediate. The Michelins outwear and stay round while doing so.

With 9 out of 10 of the most important drivability concerns fixed by tires, putting Yugo tires on your MB just cause they are round and black is asking for problems. Get a good deal on a good product but like all things you get what you pay for.

Ken & Piotr -

I did the Ali Al-Chalabi caliper road test - drive 15 miles and don't touch the brakes, coast to a stop (without getting killed on Miami's freeways), then get out and feel the rotors. Mine were cool to the touch.

Question: If a caliper were sticking or pulsating, thus grabbing the rotor and perhaps warping it, wouldn't the rotors be super hot? Mine are cool. BTW - since getting Michelins and a good alignment, the car doesn't pull anymore. It just shakes after 10 minutes of driving.

Question: With only 50k on the car, would I be looking at new struts so soon? That has been my major concern with this car - I thought the suspension components would last around 100k or so after reading so many posts on here. What's the typical lifespan of some of these suspension parts? Is my car out of the average?

Should it feel like my teeth are coming out everytime I hit a road reflector? Several months ago, the car drove like a Cadillac (sorry guys!). Now it feels like a go-cart. What's funny is that I love this car so much - if it were not a MB then I'd drive it until something came flying off the car, then I'd worry about it. But, I look forward to it feeling like a Benz again!

Thanks,

Mark E.
Ft. Lauderdale

At first , I thought your problem was a stuck caliper, which only becomes stuck after heating up for a while.Shaking would be caused by the caliper grabbing a warped rotor.However, if this were true, when you experience your problem ,your wheel would be hot to the touch,abnormally dusty, and you would feel your car holding back. I had a brake sticking problem on my Scirocco.Changed everything(pads and rotors, which were due, as well as calipers,master cylinder, lines,and finally, booster.). It was finally a pin hole in the booster diaphram. The pressure would build and brakes would stick more and more as I drove, from the diaphram not releasing.Let the car sit for 1/2 hr and cool down and brakes were fine again.
Although this may info doesn't solve your problem, hopefully it helps diagnose future problems for someone.
John