New disks old pads

[JenTay]

I was informed by the local firestone guy who rotated my tires that the front rotors were thin. He showed it to me. In fact, there is an "outer" and "inner" lip on the rotor surface. However, the pads looked brand new.

Question, is it ok to change just the rotors and not the pads? or am I asking for trouble? Any tips are appreciated.

[nhdoc]

If the wear on the pads is uniform then I would say there is no problem using them with new rotors, in fact I just did that on my 240D. It may take a couple of hundred miles for the rotors and pads to "mate" completely, or to let the minor surface irregularities in the pads wear. But even new pads need to break in so this is nothing special in the case of reusing them.

[Pete Burton]

The rotors cost more and are a little more work - I would replace them all. You might be talking about $100 total. I'm ashamed i let my brakes get as bad as I did before I fixed them, but glad I did - what a difference.

[Jim Anderson]

I think the rough surface on new rotors will quickly wear the "not new" pads to their liking.

This is a common part for reuse. Simply rough up the surface of the pads with coarse sandpaper or something before putting them in place to reseat on the new rotors.

That said, except when ABSOLUTELY new or freshly resurfaced there will ALWAYS be a lip on the edge of the rotor. I would NOT replace them on that indication alone. In fact unless you drive very hard in lots of in town driving, I wouldn't replace them at all. If you want to go by the letter of the specs, then put a mic on them and see just how thin they are.

Good luck,

[Cateaux]

You didn't say that the "mechanic" at Firestone used a micrometer, which is the only way to know for sure if your rotors are out of spec. Even if they are, I would just drive the car until a rotor gets warped and then change the rotors and pads together. One of my front rotors has been out of spec for over a year (I have a mic), and hopefully everything will be fine until it's time to change the pads.

[leathermang]

The minimum thickness allowable is stamped on the rotor.

[boneheaddoctor]

When I put on new rotors I alway put on new pads. Why..just becasue. They aren't that expensive.

[JenTay]

i assume that mic means micrometer.

no, a mic was not used. he was trying to sell me a whole brake job based only on the 'lip'. little did he know I have you guys on my side. thanks once again!

the car brakes fine with no shudder or fade. he didn't like it very much when i said i would 'think about it' . dumb blond my a$$.

[JenTay]

Originally Posted by boneheaddoctor

When I put on new rotors I alway put on new pads. Why..just becasue. They aren't that expensive.

it is when you're a grad student living your savings.

[boneheaddoctor]

Originally Posted by JenTay

it is when you're a grad student living your savings.

well my problem is the week or so you are going to have reduced braking capacity till the pad surface wears flat and smooth to match the new rotors...I totaled a car in the rain becasue I hydroplaned in a turn becasue I was driving on bald tires trying to save a buck in college.before I bought new recaps. I tore out 150 feet of metal guard rails...luckily neither me nor my brother were injured.

since then I find other ways to save money when its tight...I never shortcut on safety issues.....or what I percieve as saftey issues anyway.

[brabus]

Originally Posted by JenTay

I was informed by the local firestone guy who rotated my tires that the front rotors were thin.

The Firestone here in dallas in well known for pulling fast ones. One of my idiot friends was taken for over $1000.00 by them.

AutoZone will both turn your rotors and tell you if they are out of specs. Save yourself some green find out for yourself.

[JenTay]

Originally Posted by boneheaddoctor

well my problem is the week or so you are going to have reduced braking capacity till the pad surface wears flat and smooth to match the new rotors...I totaled a car in the rain becasue I hydroplaned in a turn becasue I was driving on bald tires trying to save a buck in college.before I bought new recaps. I tore out 150 feet of metal guard rails...luckily neither me nor my brother were injured.

since then I find other ways to save money when its tight...I never shortcut on safety issues.....or what I percieve as saftey issues anyway.

very good point. excellent example. thanks for sharing the experience.

[Ganaraska]

He's trying to rip you off. Or he is an ignoramus, possibly both. The lip on the rotor is normal wear. It could also be harmless rust and dirt buildup. It has absolutely nothing to do with needing a brake job.

To answer your question: I always put new pads on a new rotor. Partly because if the rotor needs replacing the pads are pretty well gone. Partly because in my day rotors were very expensive and it did not pay to chance uneven wear to save a cheap set of pads. Partly because I want the job to last as long as possible.

[Old300D]

Originally Posted by boneheaddoctor

well my problem is the week or so you are going to have reduced braking capacity till the pad surface wears flat and smooth to match the new rotors...I totaled a car in the rain becasue I hydroplaned in a turn becasue I was driving on bald tires trying to save a buck in college.before I bought new recaps. I tore out 150 feet of metal guard rails...luckily neither me nor my brother were injured.

since then I find other ways to save money when its tight...I never shortcut on safety issues.....or what I percieve as saftey issues anyway.

I'll definitely back you on that statement. Used pads are going to take a lot longer to break in compared to new ones, which will break in immediately as they are flat to begin with. It's not a chance I'd take given a new pad set can be had for $20.