Slotted Rotors Brake Problems

[ChuloMxcn]

So I went to my local mechanic who is usually a good dude. I was asking him how much to do a brake job all around...I still have some brake pad left, but want to go ahead and do it. He said he didnt want to replace the pads without cutting the rotors and he said that since I have slotted rotors, he is saying I should replace them with OEM.

Now I know some mechanics feel that OEM is the best way to go regardless and Im sure its a lot easier to go that way, but Im stubborn and love the look of the slotted rotors.

So my question is....is he right in having to replace rotors that often since they cant be cut and should I go back to OEM or should I just replace the pads regardless? Anybody else run into this? Recommendations?

Yea, yea....I know...."why dont you just do it yourself?" Well I live in an apartment and dont have much room to do a brake job or a jack. So unless someone wants to help me do this in the LA (South Bay) area, ill be going back to the mechanic.

[SPD_FRK]

Uhh....



Why is he even cutting the rotors???? Unless the rotors are warped, or you ran the pads down far enough to cut groves into the rotors than tell him to pound sand and take it to somebody else.

[03-Galant-ES]

you can cut slotted rotors and by changing your pads before they wear out you make it so that the slotted rotors dont warp and dont need to be cut at least not often. If this is your first or second set of pads on slotted rotors just change the pads if mechanic wont do it then tell him its fine(since you like him) and bring it to pepboys or somewhere like that they do exactly as you tell them.

I have brought my dads car to my mechanic and said fix this stuff and he said ok it should have been like 500 bucks he ended up putting 900 into it pepboys wont do that.

[deeznutz]

there's no need to cut the the rotors if there not warped i never do and if they are warped i just change them i don't bother cutting them.. just replace your pads you'll be fine if the rotors are good

[4g63lover]

As long as there are no bad heat spots you should be okay with just replacing pads.

DON'T cut slotted rotors, they may get damaged as well as the lathe you are cutting with.

[SPD_FRK]

As long as there are no bad heat spots you should be okay with just replacing pads.

DON'T cut slotted rotors, they may get damaged as well as the lathe you are cutting with.
+1

Cutting slotted rotors is not to be done at all. If the rotors are in bad shape you have to replace them. Its hard to believe the rotors are in that bad of shape to need any type of service unlike I already mentioned before.

[WhiteGalant]

x3 DO NOT CUT/ LATHE SLOTTED ROTORS!!!!

[IVORY_G]

I had my drilled/slotted rotors for 2yrs and didnt need them to be cut. Never got warped or had any deep grooves bcz I changed my pads as soon an they needed to. I recommend R1 Concepts if you need to buy more. They sell them for cheap, & you can get em delivered or go pick em up in La Habra, CA.

Good place for suspension and brakes is Avalon Wheel & Tires on Avalon & El Segundo Blvd in Los Angeles, just east of the 110Fwy and south of the 105Fwy. Ask for Miguel and tell him Will with the Galant sent you.

[polishmafia]

There is alot of misinformation in this thread.


He said he didnt want to replace the pads without cutting the rotors and he said that since I have slotted rotors, he is saying I should replace them with OEM.

In most cases, whenever you replace pads, you should either have the rotors turned or replace the rotors. Pad slapping isn't recommended, because a rotor will never wear perfectly flat. There will be high and low ridges on the rotor. Putting a new flat pad on a rotor that is worn means the pad won't be contacting 100% of the rotor, comprimising stopping ability.


Why is he even cutting the rotors???? Unless the rotors are warped, or you ran the pads down far enough to cut groves into the rotors than tell him to pound sand and take it to somebody else.

See my comment above. Yes, if rotors are warped they can be turned. If a rotor is warped, I always recommend replacement, as the rotor has a "memory" of how it warped and will continue to warp in the same fashion.


DON'T cut slotted rotors, they may get damaged as well as the lathe you are cutting with.

You are semi correct. A drilled/slotted rotor may be damaged, as well as the lathe, but it all depends on the equipment. There are lathes out there that can turn drilled/slotted rotors with no problem.

I've cut many drilled/slotted rotors on the lathe at my shop. The only time I ever had a problem was when a customer pleaded with me to turn their rotors. I said I would see if I could, but one rotor was too warped, and too much of the rotor needed to be cut. At that point, the rotors needed to be replaced.

ChuloMxcn - Did your mechanic measure the rotors? A mechanic should use a micrometer to measure the thickness of the rotor at its lowest part. If the rotor has sufficient thickness and can be cut, the rotor will still be thicker than the manufacturer's specifications. If the rotor is too thin after turning, you can run into problems with heat, limited stopping ability, and overextended pistons.

[SPD_FRK]

There is alot of misinformation in this thread.

In most cases, whenever you replace pads, you should either have the rotors turned or replace the rotors. Pad slapping isn't recommended, because a rotor will never wear perfectly flat. There will be high and low ridges on the rotor. Putting a new flat pad on a rotor that is worn means the pad won't be contacting 100% of the rotor, comprimising stopping ability.

See my comment above. Yes, if rotors are warped they can be turned. If a rotor is warped, I always recommend replacement, as the rotor has a "memory" of how it warped and will continue to warp in the same fashion.

You are semi correct. A drilled/slotted rotor may be damaged, as well as the lathe, but it all depends on the equipment. There are lathes out there that can turn drilled/slotted rotors with no problem.

Why are you suggesting that during pad changes the rotors get turned or replaced? If there is no symptoms of warped rotors, or they show signs of damage such as deep grooves from running pads to the plate...I do not see why any additional work needs to be done. Maybe I misunderstood that part of your post?

Very few shops will turn drilled and slotted rotors for reasons you mentioned (also not using the machines properly). The reaosn we say you can't turn these types of rotors is because in many cases it results in the rotors warping again, just as you have said. The whole design purpose of the drilled/slotted rotors is to reduce brake fade and warping that comes from the excessive heat while braking. If you have a set of rotors that warped, or need to be turned because grooves are being cut into the rotor surface than there are other issues to deal with starting with the brake pads.

I have yet to see anybody who runs a drilled/slotted rotor, and has done proper brake system maintenance, have their rotors machined. It is not like a lot of us are autox'n the cars heavily even that it would cause such an issue. If there is a case here it is a heavily race vehicle than the rotors are either a "cheap" brand, or they haven't picked up on cryo-treated rotors yet.



All I am going to say at this point with this topic is to me, and obviously some of the others, there is something more going on which is causing these rotors to warp or need any machining to be performed. If you want to machine them go for it, but take what has been said into consideration and when the same issues show up later on you will understand why we have said what we did.

[polishmafia]

Why are you suggesting that during pad changes the rotors get turned or replaced? If there is no symptoms of warped rotors, or they show signs of damage such as deep grooves from running pads to the plate...I do not see why any additional work needs to be done. Maybe I misunderstood that part of your post?

A new pad surface is completely flat. Run your finger across a rotor that has been used for 30,000 miles, and you will find that the surface will not be flat.

If you put a new pad on a used rotor, the pad will not contact the rotor 100%. It will only contact the high points. Highly exaggerated example below.

vvvvvvv <- Old rotor surface
_______ <- New pad surface

Do you see what I mean that the pad surface will not contact 100% of the rotor?

Now some people might say that eventually the pad will seat itself into the old rotor, but I don't think thats a proper way to perform brake jobs.


I have yet to see anybody who runs a drilled/slotted rotor, and has done proper brake system maintenance, have their rotors machined.

Hi. I'm the first person you've ever talked to that runs drilled/slotted rotors, has done all proper brake maintence, and have had my rotors turned.

I am very anal about my brakes. I typically replace them (pads and/or rotors) about every 20,000 miles (approx once a year). Since I work at a shop, its very cheap and simple. New pads, new rotors, complete brake fluid flush, and since I've had my car for over 110,000 miles, every caliper has been eventually replaced.

I bought drilled/slotted rotors a couple of years back, and installed new pads. About a few months ago, my pads were at the point of me wanting to replace them. I mic'd the rotors, and there was more than enough metal to turn them. I turned them, installed new pads, lubed all moving parts, and flushed the brake fluid. My car stops just like it would with new pads and new rotors. I had no problems turning my rotors.

[deeznutz]

If your that anal with your brakes than why bother turning them; to lose rotor thickness rotors that have been turned have a higher potential of warping. I run drilled rotors and drive like an animal never have i warped a rotor or cracked a pad never turned a rotor in my life 3 sets of pads to every rotor and i replace. Leave the anal things to your cosmetics not your brakes.

[polishmafia]

If your that anal with your brakes than why bother turning them; to lose rotor thickness rotors that have been turned have a higher potential of warping. I run drilled rotors and drive like an animal never have i warped a rotor or cracked a pad never turned a rotor in my life 3 sets of pads to every rotor and i replace. Leave the anal things to your cosmetics not your brakes.

I completely fail to see your point, or attempt to make one.

Why would I spend money to buy new rotors, when turning them is fine. If they warp after that, THEN I spend money. Its fairly simple.

And you can be anal about your cosmetics and not your brakes or any other mechanical part of your car. You'll look damn good sitting on the side of the road.

[deeznutz]

You said it yourself warped rotors have a memory so if its so cheap to do why not replace them! I like to do things right the first time and spend the extra cash cause i got it like that, and all the work done to my car is done in house by me i don't take my car to any dumb ass mechanic who just gonna try and ripp me off!!! My car never leaves me sitting on the side of the road because i do things right THE FIRST TIME thats my POINT!!!

[polishmafia]

If they warp after that, THEN I spend money.


You said it yourself warped rotors have a memory so if its so cheap to do why not replace them!

Because I don't spend money if I need to. Nowhere in any of my posts did I say that its cheap to replace parts so I just piss my money away. I can get my car in the air anyday, anytime, 24/7, benefits of running a shop. If something goes wrong with anything on my car, I fix it, but I don't spend money that I don't have to.

[03-Galant-ES]

There is alot of misinformation in this thread.



In most cases, whenever you replace pads, you should either have the rotors turned or replace the rotors. Pad slapping isn't recommended, because a rotor will never wear perfectly flat. There will be high and low ridges on the rotor. Putting a new flat pad on a rotor that is worn means the pad won't be contacting 100% of the rotor, comprimising stopping ability.



See my comment above. Yes, if rotors are warped they can be turned. If a rotor is warped, I always recommend replacement, as the rotor has a "memory" of how it warped and will continue to warp in the same fashion.



You are semi correct. A drilled/slotted rotor may be damaged, as well as the lathe, but it all depends on the equipment. There are lathes out there that can turn drilled/slotted rotors with no problem.

I've cut many drilled/slotted rotors on the lathe at my shop. The only time I ever had a problem was when a customer pleaded with me to turn their rotors. I said I would see if I could, but one rotor was too warped, and too much of the rotor needed to be cut. At that point, the rotors needed to be replaced.

ChuloMxcn - Did your mechanic measure the rotors? A mechanic should use a micrometer to measure the thickness of the rotor at its lowest part. If the rotor has sufficient thickness and can be cut, the rotor will still be thicker than the manufacturer's specifications. If the rotor is too thin after turning, you can run into problems with heat, limited stopping ability, and overextended pistons.


Thank you Pete exactly as I said above they can be turned/cut but you should find a shop with proper equipment that know how. Inorder to cut drilled/slotted rotors it is a slower spin then a normal rotor to prevent the damages many are claiming. I always cut or change my rotors when changing pads and bed the pads after changing. My G is about to be due for new pads shes been on same ones since I got her 3 years ago.

I also think Polish was trying to make the point of its cheap for him to cut all 4 rotors and replace pads with them than to replace all 4 rotors. Also cutting/turning rotors will not make them more prone to warp if they are done within spec. You being an idiot will increase your likelihood of warping.


You said it yourself warped rotors have a memory so if its so cheap to do why not replace them! I like to do things right the first time and spend the extra cash cause i got it like that, and all the work done to my car is done in house by me i don't take my car to any dumb ass mechanic who just gonna try and ripp me off!!! My car never leaves me sitting on the side of the road because i do things right THE FIRST TIME thats my POINT!!!

Your argument is poor that you should just stop now. Doing things right the first time has nothing to do with what we are discussing. You got extra cash to spend, cause you got it like that...I have a few questions for you:
Why are you driving a G mr moneypockets.
Why are you still on the same rotor after 3 pads without cutting if you do it right?
and
Why do your rims look like some stuff on local craiglist I see for like $429 for a set of rims?

No disrespect, but stop acting like you got money when it seems you kinda don't and can we please get back on topic.
OP call some local shops and ask if they can check to see if your rotors are thick enough to cut as well as if they cut drilled or slotted rotors. My local guy does mine for me at $10 a rotor he runs a mom and pop shop that I buy all my stuff from. Then throw on new pads and enjoy if the rotors are not within spec I suggest replacing them R1 are good guys I used them for my Bimmer's drilled slotted and once I do rear disc conversion on G will be using them for her too.

[HungarianHunter]

I figured I'd just post here, because my question is related...

My car vibrates when I'm braking, and gets progressively more violent as I'm slowing down...

warped rotor, or uneven brake pad wear? Or something different...

[4g63lover]

Why do your rims look like some stuff on local craiglist I see for like $429 for a set of rims?


No offense but I found this funny coming from someone rolling on Konigs...

[HungarianHunter]

No offense but I found this funny coming from someone rolling on Konigs...

I got my Falken Torque 5's for 180$ for the set of 4 of craiglist WOOT! haha

[03-Galant-ES]

No offense but I found this funny coming from someone rolling on Konigs...

I never claimed to have money have I? and you're off topic

[4g63lover]

I never claimed to have money have I? and you're off topic

Oh jeeze calm down....

[03-Galant-ES]

Oh jeeze calm down....

hehe quite calm no worries

[deeznutz]

Thank you Pete exactly as I said above they can be turned/cut but you should find a shop with proper equipment that know how. Inorder to cut drilled/slotted rotors it is a slower spin then a normal rotor to prevent the damages many are claiming. I always cut or change my rotors when changing pads and bed the pads after changing. My G is about to be due for new pads shes been on same ones since I got her 3 years ago.

I also think Polish was trying to make the point of its cheap for him to cut all 4 rotors and replace pads with them than to replace all 4 rotors. Also cutting/turning rotors will not make them more prone to warp if they are done within spec. You being an idiot will increase your likelihood of warping.



Your argument is poor that you should just stop now. Doing things right the first time has nothing to do with what we are discussing. You got extra cash to spend, cause you got it like that...I have a few questions for you:
Why are you driving a G mr moneypockets.
Why are you still on the same rotor after 3 pads without cutting if you do it right?
and
Why do your rims look like some stuff on local craiglist I see for like $429 for a set of rims?

No disrespect, but stop acting like you got money when it seems you kinda don't and can we please get back on topic.
OP call some local shops and ask if they can check to see if your rotors are thick enough to cut as well as if they cut drilled or slotted rotors. My local guy does mine for me at $10 a rotor he runs a mom and pop shop that I buy all my stuff from. Then throw on new pads and enjoy if the rotors are not within spec I suggest replacing them R1 are good guys I used them for my Bimmer's drilled slotted and once I do rear disc conversion on G will be using them for her too.

Listen my argument has never been can you cut slotted rotors it has been should you NO, ask any pro shop not your local mom and pop shop that does tune ups for 30 bucks and uses cheap aftermarket parts!!! I thought the TGC was about people helping people, people taking a hobby a craft a love for the G and doing something productive with it not sitting behind a computer screen talking tough and being a bunch of disrespectful immature little girls. MY G is my hobby my daily driver that i can mash on abuse the crap out of and throw it away when i'm tired of it... Yes i am Mr money pockets my garage holds over 200,000 in cars and bikes some of whitch you'll never see in your life sad for you but TRUE. My apologies to the rest of the TGC for getting off topic and having to sit on the sidelines and watch this baby bull crap go on.. SPD_FRK i agree with you 110% you obviously know your shit keep it up. As for this topic i'm done!!!
The TGC needs some class.....

[HungarianHunter]

I figured I'd just post here, because my question is related...

My car vibrates when I'm braking, and gets progressively more violent as I'm slowing down...

warped rotor, or uneven brake pad wear? Or something different...

:)

[00galantguy]

Listen my argument has never been can you cut slotted rotors it has been should you NO, ask any pro shop not your local mom and pop shop that does tune ups for 30 bucks and uses cheap aftermarket parts!!! I thought the TGC was about people helping people, people taking a hobby a craft a love for the G and doing something productive with it not sitting behind a computer screen talking tough and being a bunch of disrespectful immature little girls. MY G is my hobby my daily driver that i can mash on abuse the crap out of and throw it away when i'm tired of it... Yes i am Mr money pockets my garage holds over 200,000 in cars and bikes some of whitch you'll never see in your life sad for you but TRUE. My apologies to the rest of the TGC for getting off topic and having to sit on the sidelines and watch this baby bull crap go on.. SPD_FRK i agree with you 110% you obviously know your shit keep it up. As for this topic i'm done!!!
The TGC needs some class.....

Pete, aka polish mafia, is a very reputable guy and a well respected long time member. He doesn't work at a mom and pop shop at all and I would completely trust him with my galant. TGC is and always has been about helping owners, so tell me who are you... a new member... to sit here and bash a forum you hardly have a few months on under your belt.

You have made it clear that your galant means nothing to you and you will beat it till it dies and you can "throw it away" so remind me why we would take your advice?

The galant center does not need any class. We have plenty. We are people who love our g's and dont like to "mash" and "abuse" them. The only reason you have seen disrespect thus far is because you have earned it. We do not encourage people doing stupid things and getting away with it multiple times.

So guys if you want reputable advice please take from people who dont "mash" and "abuse" their galant.

[polishmafia]

Yes i am Mr money pockets my garage holds over 200,000 in cars and bikes some of whitch you'll never see in your life sad for you but TRUE.

The other cars in the parking garage of your apartment building don't count.

[polishmafia]

I figured I'd just post here, because my question is related...

My car vibrates when I'm braking, and gets progressively more violent as I'm slowing down...

warped rotor, or uneven brake pad wear? Or something different...

Where do you feel the vibrations? In the brake pedal?

[03-Galant-ES]

Where do you feel the vibrations? In the brake pedal?

Thinking its possibly uneven pad contact? I had that issue when the bmws pads were bedding right after brake job. Possibility of warped rotor on hungarians?

Does it feel localized to a side or just in general vibrations?