I have purchased a complete set of aftermarket crossdrilled brake rotors (KVR) for my 2004 S60 2.5T AWD

The front rotors are ventilated (like the OEM rotors) but to my surprise there is no distinction between the LEFT and RIGHT side. The two front rotors are absolutely identical which means that angled fan blades are turning forward on one side and backwards on the other.

The original Volvo parts (274170) also make no distinction between left and right! I am not a brake rotor expert but this simply makes no sense at all. There should be a left and right rotor so that the rotors are properly ventilated.

I am told that ZIMMERMANN makes the brake rotors for VOLVO but they claim that they are just following Volvo orders.

Has anyone heard of this "problem"?

I am convinced that there should be distinctive LEFT and RIGHT front rotors and that someone at Volvo screwed up! Volvo should issue a recall to fix this problem.

Any comments/suggestions would be appreciated.

 

If you have drilled and slotted rotors yes there should be a left and a right.Most of the time there is stickers on the rotors and instructions that say they are for one side.

The stock rotors are no different between the left or right they are the same rotor.The vent blades are straight from outside to inside.The fins are now angled.

 

No, the disks are just cross-drilled, not slotted. But the cross-drilling is asymmetrical (similar to the one on the picture) which means they should turn in a specific direction in accordance with the cross-drill pattern. Also, the "fan blades" are not going straight from the center outwards but at an angle so it would definitely make a difference which
way they are turning.

KVR and ZIMMERMANN all recognize that this is a "problem" but nobody appears to know why/how.....

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That sucks did they atleast tell you which one you have so they can send you the other one?I know the stock ones are the same for both sides.

 

That's the problem! There is no "other" one. KVR tells me there is the same problem with some SAAB, Mercedes and
BMW's but VOLVO apparently does not acknowledge the problem although it is obvious! ZIMMERMANN, who also make
the OEM brake rotors for Volvo, claim that it's supposed to be this way but they must think Volvo drivers are stupid.
This just cannot be.

I cannot believe that I am the only person in the world who has noticed this error. KVR Performance Brakes is trying
to assist me in getting some answers/explanations from Volvo and/or Zimmermann but they are avoiding the issue
and have so far not given any satisfactory answers.

Regards
Eldee50

 

That really sucks keep us posted if you hear something.

 

There is no difference between left and right on drilled rotors. The purpose of the 'holes' is to release the gases that build up btween the pads and the disc. The holes allow heat and gas to be vented. As to the 'vanes'............likewise, they mean nothing. They are there simply to keep the ventilated rotor apart.................to differentiate between a solid rotor. The cost to make a left and right would be prohibitive! Think two piece rotors if you want to see a difference in appearance.
reg

 

Thanks for your input but are you sure you are correct? I definitely hear different opinions on this subject.
If there is no difference between left and right drilled rotors, why are the rear rotors I have received from
KVR (non-ventilated) clearly marked as "left" and "right" with special instructions that they are "directional
and should be installed with the cross-drilled pattern running back from the inside to outside diameters in
the direction of rotation as 'indicated on the sketch' "?????

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Good evening eldee50. You hit 'it' on the nose. In my previous email to you I made specific reference to ventilated rotors. Solid rotors such as installed on the rear do make a difference and your 'thumb nail' is correct. I have used cross drilled rotors for years on a BMW Hartge H-3. At one time I raced SCCA events with the auto and needed the rotors for obvious cooling reasons. After the last three year restoration of the Hartge, I no longer competitively race it but do need competive brakes and so the water shedding capabilities of drilled rotors are a huge safety factor............for street driving. You will see a big braking difference with your new rotors.............just remember that these rotors CAN NEVER EVER BE TURNED DOWN. Likewise, do not wear them thin!!! The rears on my Hartge are solid with the fronts being ventilated. Enjoy your new brakes and consider a strut bar to strengthen the front suspension. There is a Canadian outfit who has an excellent product!
Reg

 

Thanks a lot for your input which is much appreciated.
Regards, Lutz in Montreal

 

yeah, i definitely agree with reg when he/she said that rotors should never be worn thin. i focus much on my volvo rotors so as to keep me and my passengers safe, especially my kids.

 

You may have an inside and outside pad, but not left and right. Even the lowest level engineer would not design something so crazy, and cause more cost in producing two extra different parts and making the manufacturing process even more complex and more expensive.