Wanted to check with all of you on this problem. 3000 miles ago or so the front rotors on the 300TD got warped pretty bad. I installed new Mercedes Benz rotors. Had a heck of a time getting the pads to stop squealing. I had installed them with Permatex anti seize compound on the pad edges and rear of the pad where it contacts the caliper piston, as I have always done. Finally had to buy the gel type anti squeal product that hardens to a caulk type material. It helped 90% of the time but still got some squealing.
check my records and found I have not replaced the calipers since I bought the car in 1990. Rubber brake hoses are 3 years old, bearings are fine, pads are OEM Mercedes. Brake fluid changed 3000 miles ago when I did the rotors. Spindles looked at when I changed the warped rotors, then seemed fine. when I replaced the rotors the pads had worn slightly off, not parallel. Thinking about them It would indicate the pistons were not moving evenly so thats where I think the problem is located.

So my plan is!!!!!
New Mercedes rotors, pads, grease, and bearing seals. Rebuilt ATE calipers from Oreilly's. Have them on the TD"s rears and my daughters 240D and no problems for 5 years on the TD and 3 years on the 240D. Carefully checked the units and they seem fine, I always check parts anytime I buy them.

Can you think of anything else that would cause this problem???
Just want to make sure I'm covering all my bases.

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

The piston fits so tightly to the bore that it has no choice but to move in a direction that is perpindicular to the pad. If it is not binding in the bore (easily checked by pressing it back with your hands), then it cannot be the culprit for the slight out of parallel wear of the pad faces.

FWIW, the '86 has developed all the symptoms of warped rotors. Each time it stops, the "cyclical grab effect" is noticeable. These were Balo rotors installed about 20K miles ago.........and I hardly use the brakes at all on that vehicle.

I have done no investigation, but, needless to say, I'm a bit miffed about it.

All the warped rotors are being caused by the "cotton gin waste" in the oil filters we have. It a Mercedes conspiricy . They want out cars to fail so we buy new ones.

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

There was a fellow who knew quite a bit about brakes and he is adamant that he's never seen a "warped" rotor. What's happening is that the pad material transfers to the rotor in an uneven pattern and accumulates at several points on the rotor. This process feeds on itself until the buildup is large enough for the driver to notice (maybe .005" or more).

I'm a bit curious as to whether he's right about that. I can assure you that the SDL never saw any heavy braking action in the last 20K miles. There is just no possible way the rotors got hot enough to "warp" themselves.

It might help you to upgrade to SD rotors and calipers since you plan to change both of them anyway. It seems that the original rotors are inadequate for the weight of these cars and since its vented, I would assume it runs cooler. So far so good on the SD rotors on mine. Its the rear brake squeel that I cant get rid off. Im going to try zimmermann rotors in there soon.

__________________
'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

When reinstalling my wheels, I'm always careful to use a torque wrench set at 80 ft-lbs (torque listed in my owner's manual). I also torque the bolts in a criss-cross sequence.

I read somewhere that if you don't it will cause warped rotors. Is this true?

__________________
Neil
1997 E300D - naturally aspirated
280,000 miles (as of November 2015)

I think I see the problem. You have to use Newton/meters when working on a Mercedes. Using ft/lbs will warp a rotor every time!!!

It's just like using a 3/4" wrench instead of a 19mm. You might think that you can get away with it.....

I'm old-school.

Anyway, my owner's manual actually lists 80 ft-lbs. They wrote especially for folks who can't convert - "those stupid americans".

I guess you answered the question..... if you don't torque properly then rotors will warp??

I assume the originator of this thread did torque properly. I've never had a warped rotor.

__________________
Neil
1997 E300D - naturally aspirated
280,000 miles (as of November 2015)

So was Newton.

Put DTI on wheel caliper mount....pre load 5mm...spin rotor...0.012' run out.
Remove rotor...put DTI tip on rotor mounting face....rotate hub...zero run out.

Conclusion = rotors don't hack it !



.

__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Anyway, my owner's manual actually lists 80 ft-lbs. They wrote especially for folks who can't convert - "those stupid americans".

I guess you answered the question..... if you don't torque properly then rotors will warp??

I assume the originator of this thread did torque properly. I've never had a warped rotor.

__________________
Neil
1997 E300D - naturally aspirated
280,000 miles (as of November 2015)

I'm quite sure that the "rotor" is the culprit. But, whether the rotor is "warped" due to the cast iron moving around or whether the rotor is "warped" due to accumulated pad deposits is the question.

How about this:

Put DTI on outside face of rotor. Observe runout and mark high spots.

Put DTI on inside face of rotor. Observe runout and mark low spots.

If amounts are just about identical and at the same positions, it confirms the rotor truly has a runout of the cast iron.

If the amounts differ and are not at the same angles, then the culprit of pad material accumulation on the surface begins to gain some credibility.

I always use a torque wrench on every bolt on the car. So I know it's not the lug nuts warping them. Also torqued the calipers with locktight.

I'll put a dial gauge on the rotors before I remove them and see if they are warped or if its a load of pad dust.


Hmmmmmm I have started using the Kleen wheel inserts, about 3 years ago. My daughters car does not have them and her brakes are fine. This time I will not install them and see what happens. But I'm changing a lot of things so it won't be conclusive about the Kleen wheel inserts. My wife and I drive the car and she is not a hard braker or a brake pedal rider like her Dad in New York. But his brakes are not warped either (Mercury Grand Marquis). So here goes the debate, did the Kleen wheels cause it ????

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

Just ONE small defect in your logic O Great One ...pad deposits of 0.012' or even 0.005' .....i don't think so...your first supposition has more cred'.




.




.

__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

The SDL has run Kleen Wheels since the rotors were installed.

But, I'm very easy on the brakes..........I simply don't believe that they are the culprits.