Brake experts - help needed!

[ayabe]

I'd like to get some opinions on this issue. Yesterday, had some new pads put in and my rotors resurfaced. For background purposes, this is the first time I've had my rotors done on the Subie but is my third set of pads.

New pads are direct replacements from what I had before, Hawk HP+'s which I've not had any issues with previously.

Anyways, performance wise the brakes seem fine, however when coming to a complete stop there is a whirring sound coming from the brakes, akin to a belt sander spinning down from high RPM.

Checked my rotors today and there are some serious grooves in them, which I believe are the cause of the noise.

I've attached pics here:

Front drivers side 1

Front drivers side 2

Front drivers side 3

Front passenger side for comparison

What has caused these grooves? Is this possibly due to incorrect installation of the pads or the worst rotor resurfacing job in the history of mankind? I'm near 100% positive this major groove was not on the drivers side rotor before I had this work performed. As I said earlier, only real problem is the noise, but I'm starting to get the feeling these pads might be getting chewed up.

Groove is towards the outside on the drivers side rotor, in case it's hard to tell.

 

[Gibson486]

you should be getting new rotors after the 2nd pair of brakes was done.....

 

[ayabe]

To clarify, I haven't gone through 2 complete sets of pads, I swapped out the OEM's with 10K miles on them and ran my previous set for the past 50K miles.

 

[boomerang]

I only looked at the first picture as that's all I needed to see. Those are machining marks from the turning. They should not be there. The widest "groove" in that first pic is chatter marks from the rotor vibrating when they machined it.

This is a warranty issue. You should go back and demand they do the job right. Unfortunately you probably will need new rotors. They should give them to you on the cheap. Perhaps credit you the cost of turning the old rotors.

 

[ayabe]

Originally posted by: boomerang
I only looked at the first picture as that's all I needed to see. Those are machining marks from the turning. They should not be there. The widest "groove" in that first pic is chatter marks from the rotor vibrating when they machined it.

This is a warranty issue. You should go back and demand they do the job right. Unfortunately you probably will need new rotors. They should give them to you on the cheap. Perhaps credit you the cost of turning the old rotors.

Thanks man, that's what I was afraid of.

 

[boomerang]

Originally posted by: ayabe

Originally posted by: boomerang
I only looked at the first picture as that's all I needed to see. Those are machining marks from the turning. They should not be there. The widest "groove" in that first pic is chatter marks from the rotor vibrating when they machined it.

This is a warranty issue. You should go back and demand they do the job right. Unfortunately you probably will need new rotors. They should give them to you on the cheap. Perhaps credit you the cost of turning the old rotors.

Thanks man, that's what I was afraid of.

In addition, they should have put a non-directional finish on the rotors to reduce noise, harshness and allow for proper break-in of those new pads. In their defense, they were probably trying to save you a few bucks. Unfortunately, whoever did the turning was either not experienced or unfamiliar with the equipment. Also, it can be difficult and sometimes near impossible to eliminate vibrations when turning. Unvented rotors are often the worst to deal with. Lastly, modern day rotors typically do not have any extra stock to even allow for machining. Inexperience, vibration, little stock to work with all lead to substandard work. They really should not have put them back on the car.

Hopefully they won't give you a hard time.

 

[ayabe]

Thanks again boomerang.

Had them turned again, smooth as silk now and no noise, also got a refund for the labor.

 

[boomerang]

Good deal! You're very welcome.