View Poll Results: What to do about the rear rotors?
Just put the new pads in and forget about the rear rotors.
8
61.54%
Replace the rear rotors with the pads.
5
38.46%
Voters: 13. You may not vote on this poll
Rear rotors...to replace or to not replace, that is the question.
Thread Starter
MBWorld Fanatic!
Joined: Dec 2007
Posts: 1,310
Likes: 8
From: Denver, CO
Formula Mazda, Beast Junior...400HP 135i
Rear rotors...to replace or to not replace, that is the question.
Just got done throwing a set of new rotors and Porterfield R4-S pads on the front of the beast. Now I need to do the rears.
The car has 25K miles so the rear rotors are in pretty good shape save for a slight lip at the top of the braking surface and a grove or two in the braking surface.
As I need to put the R4-S pads on the rear, I am debating on just slapping the pads in the calipers or replacing the rotors with a new set of stockers at the same time. I suppose a 3rd option would be to turn the rotors but given the cost of a new set, it is hardly worth it. Rotors are not even close to their wear limit.
Opinions?
BTW, I know the dealer would just slap pads in there and send it out the door.
BTW II, The AMG boys got lazy and didn't bother doing a left and right rotor so the crossdrill pattern runs on opposite directions on the left and right side. I honestly never noticed that before and always have ordered rotors by VIN so I never noticed that they had the same part number for both sides. It makes no performance difference but if Porsche and BMW can get it right, so can MB!
The car has 25K miles so the rear rotors are in pretty good shape save for a slight lip at the top of the braking surface and a grove or two in the braking surface.
As I need to put the R4-S pads on the rear, I am debating on just slapping the pads in the calipers or replacing the rotors with a new set of stockers at the same time. I suppose a 3rd option would be to turn the rotors but given the cost of a new set, it is hardly worth it. Rotors are not even close to their wear limit.
Opinions?
BTW, I know the dealer would just slap pads in there and send it out the door.
BTW II, The AMG boys got lazy and didn't bother doing a left and right rotor so the crossdrill pattern runs on opposite directions on the left and right side. I honestly never noticed that before and always have ordered rotors by VIN so I never noticed that they had the same part number for both sides. It makes no performance difference but if Porsche and BMW can get it right, so can MB!
Last edited by Blacksport350; Apr 21, 2009 at 09:42 AM.
Member
Joined: Feb 2002
Posts: 166
Likes: 0
From: Minnesota
2005 S55 1982 300dt
I did my front pads and rotors but have been holding off on the rears after several members described the extreme difficulty they encountered in removing the rear calipers. Apparently you have to get out the breaker bar to loosen the caliper bolts. I don't understand why it is so difficult.
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Joined: May 2008
Posts: 1,072
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From: Pittsburgh,PA, Cambridge, Ontario, CN
2003 S210 3.8L Brabus wagon
Locktite blue is commonly used on the bolts. Try heat with a propane torch to soften the glue and then apply pressure. It should come off.
Thread Starter
MBWorld Fanatic!
Joined: Dec 2007
Posts: 1,310
Likes: 8
From: Denver, CO
Formula Mazda, Beast Junior...400HP 135i
I did my front pads and rotors but have been holding off on the rears after several members described the extreme difficulty they encountered in removing the rear calipers. Apparently you have to get out the breaker bar to loosen the caliper bolts. I don't understand why it is so difficult.
Talk about a fight, my front rotors were a b*** to get off. I fought with the drivers side for 40 minutes while the passenger side came of with 6 sharp blows. I know all the tricks in the book and that one just wanted to give me hell.
Next thing you know, I will come out to my garage and it will be covered with 100 frogs and have a picture of Allanlambo on the screen with his spiderman statue.
Super Member
Joined: Aug 2003
Posts: 626
Likes: 3
From: Los Angeles, CA
'03 E55 (My Daily), '01 ML 320 (Wifey), Twin Turbo '69 Camaro (In Progess)
I agree with Jangy on this one. Rear brakes are not responsible for much of your stopping power and the lip on the rear rotors (albeit a small one) shouldn't have any effect on braking. You should be able to run through two sets of pads before you need to replace a rotor.
You make a good point. By MB casting a "one size fits all" rotor for the fronts, the cooling vanes do not turn right direction on one side. It's not a major issue to me, but you'd like to think they would get it right, especially on an AMG car.
BTW II, The AMG boys got lazy and didn't bother doing a left and right rotor so the crossdrill pattern runs on opposite directions on the left and right side. I honestly never noticed that before and always have ordered rotors by VIN so I never noticed that they had the same part number for both sides. It makes no performance difference but if Porsche and BMW can get it right, so can MB!
Thread Starter
MBWorld Fanatic!
Joined: Dec 2007
Posts: 1,310
Likes: 8
From: Denver, CO
Formula Mazda, Beast Junior...400HP 135i
I agree with Jangy on this one. Rear brakes are not responsible for much of your stopping power and the lip on the rear rotors (albeit a small one) shouldn't have any effect on braking. You should be able to run through two sets of pads before you need to replace a rotor.
You make a good point. By MB casting a "one size fits all" rotor for the fronts, the cooling vanes do not turn right direction on one side. It's not a major issue to me, but you'd like to think they would get it right, especially on an AMG car.
You make a good point. By MB casting a "one size fits all" rotor for the fronts, the cooling vanes do not turn right direction on one side. It's not a major issue to me, but you'd like to think they would get it right, especially on an AMG car.
As to the one size fits all, I assumed they were straight veined but if not, that is a bit of a FUBAR! Directional veins running backwards are not a great idea but on a street car it is probably not a big deal.
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Super Member
Joined: Aug 2003
Posts: 626
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From: Los Angeles, CA
'03 E55 (My Daily), '01 ML 320 (Wifey), Twin Turbo '69 Camaro (In Progess)
BTW, I am going to do the same thing shortly, as I just recently did front pads and rotors and my rear set needs need pads. Where did you buys yours at? Am looking out there for some good deals.
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MBWorld Fanatic!
Joined: Mar 2006
Posts: 4,278
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From: San Jose area
'19 E63S sedan
It looks like I will just pad slap it based on the comments.
As to the one size fits all, I assumed they were straight veined but if not, that is a bit of a FUBAR! Directional veins running backwards are not a great idea but on a street car it is probably not a big deal.
As to the one size fits all, I assumed they were straight veined but if not, that is a bit of a FUBAR! Directional veins running backwards are not a great idea but on a street car it is probably not a big deal.
Thread Starter
MBWorld Fanatic!
Joined: Dec 2007
Posts: 1,310
Likes: 8
From: Denver, CO
Formula Mazda, Beast Junior...400HP 135i
Thread Starter
MBWorld Fanatic!
Joined: Dec 2007
Posts: 1,310
Likes: 8
From: Denver, CO
Formula Mazda, Beast Junior...400HP 135i
The OEM pads are at 40% thickness.
Off to the garage to slap new pads on the old rotors.
Out Of Control!!
Joined: Sep 2004
Posts: 13,394
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From: San Diego
2015 S212
Actually, the fans are straight out, if I remember them right. But to your point, even straight is not as good as pushing air through..
Super Member
Joined: Aug 2003
Posts: 626
Likes: 3
From: Los Angeles, CA
'03 E55 (My Daily), '01 ML 320 (Wifey), Twin Turbo '69 Camaro (In Progess)
I took a look at mine (OEM) and they are curved, with the driver side vanes not running the right direction to maximize airflow. Am sure there are plenty of mfgs who may make them with straight vanes. I don't track the car, so they'd never get hot enough for the design to be a major issue.
