andrew n

I just had my 94 GSR front brakes done (new pads, and rotors turned) a few months ago and my rotors are already warped. Will I have any problems if I just have the rotors turned again without new pads, or do you need new pads to match the resurfaced rotor?

Thanks

reefer_bob

Don't be scared to use a torque wrench on the wheels. That's the leading cause of warped rotors.

You have to be careful of how thin your rotors get. They can only be turned so many times, and if they're warped, they may not be able to be turned down enough... Off topic, but worth mentioning.

It is recommended to put on new pads. If your rotors are warped, think what it could have done to the pads. But if you have very limited miles on them, you can reuse the pads. I would take a block sander, and scuff them just a little bit to take any irregularities out of them. Just a little scuff, and then properly break in the breaks. Accelerate to 40, and an easy brake down to 1-2 mph. Don't stop. Then repeat a couple more times. Try not to mash on the breaks for the first 100 miles or so.

Brake Pads are cheap, and important. If it were me, I'd put on new pads, but that's me. You should be ok.

Reefer_Bob.

bps2799

That you've warped your brakes after having the rotors turned doesn't lead me to recommend turning them again. Turned rotors are more susceptible to warpage.

Did you bed the pads in?

Pads OEM or aftermarket?

Do you let your brakes cool off?

Tell us about how you use your brakes.

andrew n

I used OEM pads, and dont really use the brakes that hard. I am usually very careful to let them cool, and I dont sit on them in one place after a long hill. Also, this was my first pad replacement and that was at 115,000mi. I only have 6K since the brake job. Do fronts usually last 115Kmi, how about rears...I am still on the original ones?

Thanks

bps2799

Brakes will last how you use them. The rears do less work than the fronts, but are of a lesser compound (OEM) than the fronts, so it's hard to tell. I'd recommend changing them, probably w/ AEM Nissin ceramic or something semi-metallic (Axxis metal masters) like the fronts and consider this the last brake job you'll need in the rear for some time, assuming the guy puts enough molykote grease and the proper shims back to keep the squeal away.

The rotors should be changed if you've put 115K on them, since anything will wear after time (and think about all the heat cycling stress they've endured). You probably don't have enough left to turn them again and still be in spec. Check the rear rotors for proper specs at the same time you replace the front rotors.

Last ?, which is that in the post I quoted, it sounds like you make the brakes do most of the work when going down hills, as opposed to downshifting. I'm hoping not.

GSRaCeRbOI

everytime you turn your rotors your taking off material/making them thinner.. there is a service/throwout/discard limit stamped on the rotor.. and everytime you turn them their also more prone to warpage.... w/ 115K miles on your car I'd go ahead and replace the rotors.. its a relatively easy job that can be done by yourself.. i just did mine... replaced my rotors w/ Brembo blanks/solids and Hawk HPS pads.. make sure you bed/break correctly.. my Hawks came w/ instructions on how to do this.. basically you get up to approx 40 Mph.. then do a series of slow downs, but dont stop completely (unless you have to of course)... then you let them cool down...
make sure that you torque your lug nuts w/ a torque wrench and if you take it to a shop that they dont over torque them (very common In my experience) when they go crazy w/ the impact wrench... ask them to hand tighten it or tell them your not paying... also make sure you dont wash your car after a drive because the hot brake pads/rotors and cold water could cause them to warp and the part that the pads/caliper sits on retains more heat so after a hard drive don't park/let it sit..let them cool down first..

bps2799

One point to mention about the torque wrench. It doesn't read accurately if some knucklehead has already used the impact wrench to tighten the lug nuts to 2000 ft-lbs.. already. That is, of course it will break over at 80 ft-lbs, since it has been tightened another 1920 ft-lbs beyond this threshhold (facetious example, of course).

I had to bitch about this when getting a tire replace this weekend. You can buy a cheap torque wrench to check that the lugs are tightened properly, since +/- 5 lbs. wouldn't really matter.

I carry my own torque wrench with me. Scares'em.

GSRaCeRbOI

I usually do my own work unless its not possible like getting new tires.. since I dont have a tire press.. i have to take it to a shop.. but I always watch them...
I tell them to tighten it by hand or else I'm not paying.. I always stand there and watch them.. then they always say sum BS like you cant stand in the shop for insurance reasons.. so I stand outside of the garage behind my car and watch them..and they cant say anything...

I carry my own breaker bar and torque wrench in my trunk (easier to take off my rims and torque them correctly incase I get a flat in the middle of nowhere or something) and I tell them if they dont have one to do it by hand.. I can supply them w/ one.. all the shops i've been to they have listened since Im standing right there and told them in advance I wasnt going to pay them unless they tighten it by hand...

yeah thats true.. if its tightend to say 150 ft-lbs w/ an impact wrench.. then they re-check it w/ a torque wrench of course its going to click over at 80 ft-lbs... so make sure they put the lug nut on by hand to start screwing it in.. and then tighten it w/ a torque wrench... no impact gun.... i've seen them do other cars while doing mine.. and sometime they just place the nut into the impact guns socket.. then place it up to the lug bolt... I wonder how many people had mistreaded/crooked/broken bolts these are the cars where the owner is in the sitting area.. or just dropped off the car and left..

ken

I didn't read the whole set of replied since I'm lazy, but you do not want to put new pads on fresh rotors. I cannot find the link that explains all the reasons why, but it is mainly because they won't be enough "tough" material between the two to create the proper stopping friction. In normal brakes, some of the pad material gets into the rotor and helps create friction. When you turn your rotors, you want old pads so that it can transfer that material back to it. Just like when you get new pads, you want old rotors to help wear away that top layer on the pads.

Rule of thumb:
1. New rotors, old pads.
2. New pads, old rotors.

If you want, turn your rotors and then put on new pads like a week later. Should be just fine then.

reefer_bob

Gotta tell ya Ken, I've NEVER heard of this one... I'm not saying your wrong, or flaming you, but that goes against everything i've ever heard or read about doing brakes. When you resurface a rotor, it comes out rough. Sure you've gotta rough everything up to make sure they seat properly, but I've never done the job half way. New pads, new rotors. New rotors, new pads. It's a given to me. If you can show me else wise, please do!

ken

Found one of the places I've heard it: http://integra.vtec.net/geeser/brakes.html (down at "Warning! New on new is bad")

I've also read about the technical aspects on a manufacture's website, but no way I'll be able to find that again.

reefer_bob

Decent article. However, I maintain that if brakes are proplery broken in, multiple 40mph - 1mph stops, they will seat themselves fine. I will do more research on this though... Thanks for the insight!

ken

The other article I had seen talked about doing that to brake in new pad/new rotor combos. Like 40-1mph braking, 70-40mph braking, and doing it over and over again with a period of cooling in between. That is the proper way to do new pad/brakes, guess the key is to not expect to have your excellent braking right away with fresh stuff.

reefer_bob

No, the worst thing to do to new brakes in go right out of the chute, and bash on them. Same deal with clutches and new/resurfaced flywheels...

SIK IN DA HED

just buy new ones. summitracing sell the OEM style ones made by Brembo. they only cost $30 each. cheap man... get some...

bps2799

You need to "season" your (NEW) rotors before you bed in your pads, by driving and braking gently for around a couple hundred miles to get the new rotors heat cycled properly.

Bedding in is stressful on new rotors until the seasoning process is done.

It isn't that bad to go new on new, but expect several hundred miles to get things mated and seasoned properly before you use the brakes hard, such as in bedding the pads.