Brake Rotors

[kwmir]

I recently started getting this grinding sound when I back up on my 2003 KJ Sport. i took it into the workshop to get looked at and the guy told me that the rotors and brake pads were shot and would have to be replaced. I was underthe impression that the rotors can be tooled down at least the first time and eventually have to be replaced. He told me that the rotors on the KJ have can not be tooled down since they are made of composites. Is that true? I thought that composite rotors only come in high performance sports cars. Could someone please shed some light on this issue. Thanks

 

[kjpilot]

I guess steel is a composite of iron & carbon, but that is probably not what he meant by composite. You won't find composite rotors on a vehicle with a new sticker price of $25K.

 

[dnm45227]

it may be true about not being capable of being machined. if the amount of material is too thin to accept resurfacing, then they must be replaced.

think about how much pressure is put on the rotor by the piston, although you would stop in a hurry if the piston penetrated the rotor you wouldn't want it to happen.

 

[myjeepwalks]

Do you need front, rear or both?? Either way I seriously doubt you have composite rotors. Unless they changed them from 02-03 or you have some special edition liberty or something they should just be regular rotors. The rotors are able to be machined as long as they're thick enough. You said they were grinding so they may be grooved pretty good and not have enough material to machine them smooth. These days rotors are so cheap alot of shops just want to sell you both pads and rotors. They can do a brake job alot faster not having to wait for the machining.

When i put front brakes on my 02' i priced rotors and for $32 each from advance autoparts it wasn't even worth the $15 each to get them machined. I just bought the new ones. I've had them on over a year, gone 30k miles and no problems. If they were composite i'm sure they'd be alot more than $32 each.

 

[JC]

I used to run a repair shop a few years back (before I got the bright idea to get into IT), and we ran into this every so often. A composite rotor is one that has one material (usually stamped steel) for the hub part, and a traditional cast material for the actual rotor disc in an effort to save weight. It's really not so much that you can't resurface them, but you have to use the right equipment, which is different and most shops did not have. In our shops case, when we tried to resurface them, they would chatter on the lathe and get all gouged, ruining them. I'd usually get the customer to buy new rotors that were all cast so the next brake job it wouldn't be an issue.

 

[JeepJeepster]

I had my front rotors resurfaced no questions ask. I had a slight vibration when braking.

Many times the pads will wear out and if its not caught fast enough, the rotors will be destroyed.


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