I’ve been needing to change my brake pads for quite some time now, and I just noticed (had to turn down the radio) that I’ve got that nice metal-on-metal grinding sound.
If I have grooved my rotors, what damage will I do if I just change the pads and wait to change the rotors for a month or so?
Anyone?
I have seen some chewed up rotors that looked like hell and worked OK. If you plan to change the rotors in a month, just do it all right now. The new pads will begin to form to the shape of the worn rotors and those used pads should not be used on the new rotors.
new rotors are normally much cheaper than having the old ones resurfaced. They go on pretty easy too. Famous last words.
It’s not recommended because, as noted, the new pads will conform to the shape of the rotors pretty soon and you’ll need to replace them again when you replace the rotors. Also, initially you’ll have diminished braking power as the pads won’t make full contact with the rotors.
That being said, I’ve done it in response to budget exigencies. My brakes worked.
About all that will be harmed by putting new pads on grooved rotors with the intent of replacing the rotors next month is that you’ll be buying another set of pads next month as the pads will by then have become a reverse image of the rotors with ridges corresponding to the grooves. Ridged pads on new, flat rotors will leave just a thin line contact and not enough braking power.
Rotors are usually fairly cheap and usually pull right off once the caliper’s out of the way. This isn’t a really good place to be guessing - Twenty bucks for a Haynes or Chilton book for your car would be a good investment.
You didn’t say what kind of car you have, but some are notorious for having thin rotors that just don’t have enough thickness to be “turned” so they have to be replaced, whether or not they’re grooved. VW seems to lead in this dubious practice.
I believe that if you go to a brake shop they will not put new pads in brakes with “badly” grooved rotors. I don’t know just what constitutes “badly” but I’m sure there is a spec in the vehicle code about brake rotors.
One problem might be that the thin sections will result in dangerous rotor cracking and warping as a result of differential heating and cooling.
Huh? Machine the rotors for $10 each, or two new ones for $90 each?
Once rotors reach a manufacturer specified minimum thickness (usually cast into the steel) they cannot be turned again because the mass is incable of dissipating the heat of braking.
Replacing pads before the rotors become scored is smart and safe motoring. Truing a smooth rotor and taking .015" for a brake change is vastly different from taking .080" to make the disc true.
Hey, it’s your wallet.
This is sometimes true, but not always.
On some rear wheel drive vehicles (like Ford Rangers, for example), the rotor is integral with the hub. These suckers are not cheap. Ranger front rotors from the late 90’s models are about $75. Each. You replace these if you really need to, but not just for the hell of it. 
I just checked for a 2000 Civic (which my wife drives). Raybestos PG Plus rotors for that car are $34.99 each online at Kragen. Resurfacing tends to run about $10 per rotor, in my experience.
All my life I’ve been a victim…my experience consists of brake shops charging $90+ to turn 'em…per rotor (I’m embarassed by this now, but in the name of fighting ignorance I will push on) and then rolling their eyes should I inquire about the cost to simply replace them, “Naw, man, that’d be way expensive.”
As I grew and tumbled through adulthood I discovered that the damn things are (usually) pretty cheap. So when My wife started tearing up her rotors(last guy to do the brakes didn’t install the wear indicator ‘crickets’) on her Camry I became a hero by replacing the front pads & rotors for about $45–total. I billed her good later for the labor, but that’s a different thread.
Now I’m hearing that, not only was I getting lied to about the price of rotors, but I was getting totally balled on the cost to turn the old ones! :mad: Remind me to throw a post into GQ next time I’m buying anything.
I just got my brakes done, and the time to turn a rotor was quoted as 45 minutes. At $60 per hour, that’s not cheap.
They were going to charge you labor for the whole time the rotors sat there spinning on the lathe?
I’ve been doing brakes for 20 years on numerous rust buckets.
I’ve never been overly concerned about grooved brakes. If the grooves aren’t too bad, I just slap on some new pads and get on with life. If the grooves appear deep I simply replace the rotor. No biggie.
Appologize for the hijack, but what is it with women and brakes? My wife goes through a set of brake pads about every 12 months! And it doesn’t matter what kind of car she’s driving. A buddy of mine has the same problem.
Just to make sure we’re comparing apples and apples here…
The $10/rotor figure I gave was what I was charged when I walked into the garage with rotors in my hands. (Figuratively, I suppose. Ranger hub/rotor assemblies are pretty heavy and I took 'em in one at a time. ) The point is that I’d taken them off the truck myself. The price is sure to be higher if they’re doing that themselves.
This was at a Pep Boys - a place which I probably won’t go to again for this because they somehow machined in a large amount of runout, where there had been basically none.
“Hey, for $10, ya get what ya pay for.” Perhaps, but I don’t think their rate was particularly low. Based on my understanding, it’s not a particularly labor-intensive job. The tech gets it chucked up on the lathe, starts it, and walks away. Like Berkut said, billing for “labor” while the machine runs unattended seems kinda shady (and should certainly price them out of the market). I’ve not seen one that does: Most places I’ve checked advertise a flat rate per rotor, and like I said $10 seems pretty typical around here.