Took the car in for rear brake squealing.. Got the new pads... Squeals like mad now, wonder why? : / Not sure what to do/say about it. I seriously doubt another dealer would touch these rotors now. And not sure I want to take the car back there.

notice, some of the gouging is pretty deep





thoughts?

 

deng,this is what they call resurface?
the right way is to mount rotor on the little machine like the lathe.then the rotor turns while a tool with carbide tip slowly cut from both sides of the rotor to ensure even,parallel cut.
from what i see there is someone with the disc sander and sand the hell out of the rotor by hand.consider it very unfrofestional and unsafe because the pads can't put a good grip on the surface.
i would take this matter to farther action.good luck

 

What in the hell did they do to your rotors?

This is not good. Photos are the first step to documenting this problem. I would suggest you demand that they send the rotors to a QUALIFIED shop to do a proper resurfacing. Threaten them with a lawsuit if they don't take care of this problem (as well as notification of BBB, Infiniti Corporate, etc.). Document everything in writing and with non-digital pictures (digital is too easy to manipulate at not admissible in some courts).

You are paying for a service which they obviously did not fulfill.

 

they were not put on a brake lathe, looks like it was done with a 1/4 in die grinder with a 3m roloc disc,
just had 4 wheel brake job done on warranty last week, told tech i would tip him $20. if he replaced front rotors. picked up car and they resurfaced rotors so no TIP

 

Did an Infiniti dealer do this work? I'm no expert on brake resurfacing, but it looks like a hack job to me.

 

I'd make whomever performed that abortion replace the rotors. If it was a dealer, I'd report them to Infiniti.

'04 G35 Coupe DG/G/5AT/Premium.

 

From what I hear the runout on the G35's brakes are rather small. I've heard it was actually recommended that they are not turned unless it is warped. Turning a rotor takes away mass from the rotor which helps to keep temperatures down. It's easier to warp rotors that are closer to runout then new rotors. If this is the case, then it's actually better to sand the disc this way then to try to bed a new brake pad on a glazed rotor surface. Those marks will dissappear after a bit of use.

 

The inner and outer metal surface of vented rotors is at least 0.35" thick, so a light trueing cut of 0.003" is less than 1% [0.85%] per side. The pad working area is about 45-50% of the total rotor mass, so each very precision cut reduces rotor mass by 1%. This 1% decrease in mass translates to a 1% increase in temperature rise.............6F in 600F.

The 1 mm wear limit is a ~~10-12% decrease in mass......for a 60-70F temp rise.

Obviously turning [trueing] the rotors must be traded off with ultimate life.

The usually problem is lack of precision and rushing the job, therefore removing more than necessary on the first pass to avoid the possibility of having to do it over again. Because warranty pay only allows enough time for one cut. So instead of 0.003" the average tech starts with 0.01" taking 3-4 times more off than needed with frequent trueings.

A couple of hack jobs like this coupled with natural wear and the rotor is worn out.

I can true my rotors 6 times [every 6-7,000 miles] and still be above minimum thickness at 40-45,000 miles.
The gray cast iron rotor material fatigues anyway in 2-3 years, if you are an aggressive braker.

Members might find this rotor design tutorial helpful: 97 pages of slides.
http://www.sae.org/events/bce/tutorial-ihm.pdf

Gray cast iron rotors maintain their properties to 500C [832F], you will learn more about rotors than anyone at dealership knows.
http://www.gunite.com/literature/pdf/discbrak.pdf
http://www.me.cmu.edu/faculty1/wicke...ling%20JSV.pdf
http://www.delphi.com/pdf/techpapers/2000-01-0445.pdf

A basic 110 page brake tutorial:
http://www.sae.org/events/bce/tutorial-limberg.pdf

 

That is NOT what resurfaced rotors should look like. You should see an even crosshatcing. I watch my mecanic friend do it all the time. Here is a picture of my Brembo rotors. They are slotted but you can still see the xxxx I was talking about. That wears away over time and needs to be replaced.




If you look closely at those pictures you can see the xxxxx. That's what a resurfaced rotor should Have. Not yours with the ((()()(--\\

Thanks - Joey Avino

 

A normal brake lathe will not leave a cross hatch pattern. I believe it can be done if you use the machine used to resurface flywheels though.

 

Sorry to dig up an old post. But that's what a successful boolean search does...

I decided to get the brakes checked one last time on the 3yr/36k brake warranty for my '03.5 sedan. The work order stated the FRONT pads were changed and rotors resurfaced, but they used the REAR pad part number. Upon closer inspection, it looks like the REAR calipers were cleaned, and now the REAR rotors look exactly like the pictures above!!! It looks like they used an angle grinder on them, leaving swirl marks/grooves everywhere. So much for quality service at the dealer.

I checked the service manual/brake section and couldn't find any documentation on what the "proper" way is to resurface rotors. Does anyone have the exact page/paragraph/etc I can quote? Should I demand new rotors? Is it wrong to expect resurfaced rotors to be perfectly smooth?