SSucese

iTrader: (1)

Okay lemme first start out by saying about 2 months ago a co-worker of mine asked If I could put on some new rotors and pads for his Grand Am in which I replied I had no problem doing so. So anyways to make a long story short just the other day he was complaining that he was getting heavy vibration in the steering wheel upon braking @ highway speeds which you would normally think would be warped rotors, however I had just installed him new disc as mentioned above and it basically lead to him taking the car in to a local mechanic being that he wanted to get the issue resolved ASAP. So just as Im getting ready to leave work his mechanic calls him and tells him his rotors are warped and which my co-worker replied how could they be warped when I just put new ones on not even two months ago? The mechanic's response was well who did your brake install beacuse I would like to know why he didnt turn the rotors upon after paying for new ones? Now to be honest that pissed me off because maybe im wrong but I have never heard of anyone getting the rotors machine turned right away after buying new ones So thats why I came here to pose the question to anyone else why in the hell would you turn disc when new?

camaroextra

iTrader: (10)

thats crazyness. how do you think they machine the face to where it is? dur turning it. tell him that, it makes sense.

garrettpen

You wouldnt. I work at a local parts store and even our cheap ones carry a 1 year warranty. I would take them back and make them warranty them for manufcturer's defects.

smoknta

Actually alot of shops will turn them slightly to make sure they are a true flat surface. Only taking off about a thousandth or two. I have seen more than a few people do this. But I cant see not doing it causing your rotors to warp.

TransAm12sec

Yea, I've heard of turning new rotors before. After a google search, the main idea is not to turn them. I think if it has a zinc coating you should, or ride the brakes easy for 500 or so miles.

jam01

a couple of questions for you. did you clean the rotors, scuff them(cross hatch with a wizzer) new pads, how about breaking in the rotors.and yes some people cut the rotors as mentioned above. all rotors come with a coating on them, and that must be cleaned off with brake clean. i hope this helps.

RollTideTA

Installed three different sets of rotors on my own cars and one disc brake conversion kit onto my ATV. Never was I told by anyone to turn the rotors. Only do the brake pad seating stops.

I didn't turn any of them before installing. Haven't had any trouble with lots of miles on these so far. Used the expensive pads with the lifetime warranty, but besides that nothing special was done.

Im sure after the fact its easy for most people to say you should have had them turned, but most people around here dont. I asked my dad, who is a mechanic at a honda dealership here, and he said that they never do either and can't remember having anyone come back with that problem. He did say that some brake shops might especially if the rotor quality was in question.

Rotors should be machined true to start with, if they aren't most have a warranty.

SSucese

iTrader: (1)

Yes I did clean and wipe them down good before applying the calipers and new pads to the disc. However I just dont understand why anyone would go machine turn new rotors that have 0 miles on them? Thats definitely a new one for me Well see however because I have yet to talk to my co-worker and probably will not do so till Monday when we get back to work and by then I will find out if his mechanic by turning these nearly new rotors even helped the situation or not.

1badragtop

I work in a shop, and I have seen rotors come new warped- mainly from being stored improperly on the shelf. However in your case I would suspect debris behind the rotor causing an untrue condition, while the rotor is fine. I would make sure there is no rust on the wheel hub before mouting the rotor,and if available, use a dial indicator to verify the hub is not out of spececification (less than .001" usually). then mount the rotor and do the same ( less than .003" at the out edge usually). If either is out of spec. replace the faulty component.

0rion

iTrader: (1)

I've been doing brake jobs on my own cars my entire life and I've never turned a new rotor. As I was reading your first thread I was wondering how much you torqued the lugs down? I also was wondering if the driver of the car did some high speed stops. Either of which will warp rotors, especially new ones that aren't broken in.

Jeffs99SS

I worked in a shop for about 5 years, and we'd always put new rotors on a lathe before installing them. Like said before, the idea isn't to take much material off... only a couple of thousanths if needed to get them perfectly straight. It's better than having to redo the brake job if you have a pulsation on a test drive.

However, since it didn't do it until after a couple of months, I was also thinking that maybe he was doing some high speed stops or didn't break them in properly.

THE CHOP SHOP

iTrader: (7)

Yeah i would go with the high speed stops problem. I have done a few full brake jobs and the last one I did I used the cheapest rotors and pads possible. I have heard of turning them before installation and I was curious because I looked at the more expensive set before I got these and they looked like they were cross hatched but the valuecraft ones where not. Once I looked closer they had a sticker that said do not turn before installation. Everything turned out fine and no pulsating has occured after 500 miles.

ace68

iTrader: (15)

I;m thinking High speed stops otherwize she would have felt the problem right after the install not 2 months later.

GXP Lover

I've recently redid my brakes before I put her away for the winter and as I was doing my traditional brake-in, the rotors warped. Usually, I don't cheap out on the rotors as I track my car occasionally and this time I did. I mean seriously, how can you pass up Chinese rotors at $12/pc? Well, I will from now on. I would bet he bought the cheapest rotors he found, Chinese, and they aren't up to snuff, as they say. Now I have another project for the spring...

firefighter

The only thing I can think is that it is one of the following or a combo of the following cheap rotors and or you may have "blasted" the lugs on with an impact gun. If this is what you did don't feel bad. I did this to my girlfriends car while I was a mechanic at a Chevy dealer. She had an '87 Sterling 827S or somthing like that and I warped 3 sets before someone told me to be carefull with the rotors on FWD cars actually I found out after some research it is really any rotor/hub type set up but in the early '90s it was mostly FWD's that had them. What I do now is I set up the gun to a low setting and then use a 24" breaker bar to tighten them down the rest of the way check after a few 100 miles and your done. just my opinion.

firefighter

Oh and if thats not what you did sorry for the long winded useless answer.