Violent shaking upon braking..

[opponheimer]

My alignment is off pretty bad.. but this started happening after I converted to 300zx front brakes. I used brand new rotors and pads, however used aluminum calipers.. Could one of the pistons on the brakes be stuck? or is it possible the NAPA calipers I got are not round?

Who knows what to look for first?

[kyo_kun187]

that happend to me one time.. my rotors where bent.. so check to see if there bent or not

[jskateborders]

usually warped rotors. If you got a reman, It may have been incorrectly turned. Run a caliper around it. Also, Are the mounting holes the same distance from both sides of the pad when you mount it.

[opponheimer]

Ok I just had both new rotors turned, and pads replaced, bled both systems, and i'm still having the same shuddering upon breaking at higher speeds. Could there be an issue with the caliper(s)? and is there any special way to test for the issue without having the car in motion?

[sac]

its just shaking when your breaking? Not all the time? If its shaking all the time it could be a seperated tire, bad bearing, bad front end parts. I would check into the calipers.. Sounds like that could be the culprit if its only shaking when your braking. Unless you have abs and your abs unit is pretty fu*ked up.

[HS13KLS]

so only when your braking?...driving on bald tires?..i was for a while and it made my car shake a lot...if you bought those calipers new im sure there is a warentee..i bought my z32 30mm allum. from autozone and i had a warentee. id say if you do return them..i hope that helps a little

[g6civcx]

I've never spent money on resurfacing. I just buy new ones at the same time the pads gets replaced.

$20-30 per disc is affordable enough with safety items like brakes.

[pbcstylez]

i think oem brembo blanks work just as good as you cross drilled rotors and are around 30-50/ea

I think this is what g6civicx is trying to say

[aznpoopy]

cheap ass blanks are fine. buddy ran raybestos autozone whatever rotors with some ridiculous high heat race pads for hpde. he's group 2 or 3 last time i talked to him., which was a while ago. no problems at all.

when you buy super high price cross drilled and/or slotted rotors, you just wasted alot of money.

op. what kind of work have you done to your tension rods? did you bed the pads properly?

[opponheimer]

I've never spent money on resurfacing. I just buy new ones at the same time the pads gets replaced.

$20-30 per disc is affordable enough with safety items like brakes.

I surfaced them myself on a company lathe for free... I think this is going a little OT with which brand rotor is better. Anyways, could I be using the wrong rotors or something? I can't remember which ones I purchased but I have the aluminum 26mm calipers, so I think only one type of rotor will fit correct? The shaking seems to be coming from the front right.

[Phlip]

you must buy the cheap ass POS rotors that are made in china dude...

when you buy high quality drilled rotors they last longer, improve breaking, and are alot more expensive. Proper Resurfacing of the rotor doesnt weaken it, damage it, or make it un-safe.

or you could just be a cheap-ass, and buy POS rotors everytime you change your brakes. Personally, my life is worth more than 30 bucks.. So i buy higher quality pads, calipers, rotors. But it works for some people..
The $20.00 "POS " China rotors you speak of have always stopped my car with no worries, where I have often worried about removing MORE thickness with turning... In such, I have NEVER EVER FUCKING EVER used a turned rotor. Not when NAPA charges the same for new ones as it would cost to get them turned. PADS is where you lay down the cash.




Back to the task at hand...
Are you over-tightening your lugnuts? That can warp and ruin a brand-fucking-new rotor.

[g6civcx]

whoa, take it easy.

If you want to say that drilled discs perform better, post your findings. If you insist that one stops shorter than the other, post your test data.

This topic has been covered many times. No need to beat down others.

[sr20powerd]

The $20.00 "POS " China rotors you speak of have always stopped my car with no worry, where I have often worried about removing MORE thickness with turning... In such, I have NEVER EVER FUCKING EVER used a turned rotor. Not when NAPA charges the same for new ones as it would cost to get them turned. PADS is where you lay down the cash.




Back to the task at hand...
Are you over-tightening your lugnuts? That can warp and ruin a brand-fucking-new rotor.
Truth, especially if they have a lifetime warranty so if the do warp, you get new ones. No questions asked.

[opponheimer]

No I am not over tightening my nuts.

Seriously though. I'm about to put the stock brakes back on and see if I have the same issue. Tires are not bald btw.

[projectRDM]

you must buy the cheap ass POS rotors that are made in china dude...

when you buy high quality drilled rotors they last longer, improve breaking, and are alot more expensive. Proper Resurfacing of the rotor doesnt weaken it, damage it, or make it un-safe.

or you could just be a cheap-ass, and buy POS rotors everytime you change your brakes. Personally, my life is worth more than 30 bucks.. So i buy higher quality pads, calipers, rotors. But it works for some people..

A rotor is a rotor. If it's cut on a straight lathe, I could give a fuck if it costs $5, it's a straight rotor. This nonsense about having to buy $100 rotors with pretty vanes and holes is absolutely stupid. Get that shit out of your head. I buy NAPA blank rotors and have for over 15 years, never had an issue with warping unless I boil the fuckers on a track. ANY rotor will do that. I tried $139 cross drilled rotors from Stillen back in the day, they warped just like the NAPA blanks do, just like my friend's AP Racing's did, just like the Stoptechs on another Z the same day. Heat kills any rotor, and a drilled rotor will warp faster because it can't dissipate as much heat as fast as a solid one.
Additionally, a properly maintained car, even with 'POS' rotors will rarely ever need to have them replaced unless they do warp or see damage from the pad's backing plates when worn too far.

I'm going to go out on a limb and suggest two possible culprits, pad knockback or a worn wheel bearing. Either of those would cause symptoms as described.

[aznpoopy]

last time i checked.. checker/kragen carries raybestos..

you ever felt the difference between a cheap blank rotor, and a high quality drilled rotor? Why the fuck do you think evo's, sti's, benz, bmw, etc.., etc.., etc.. run drilled rotors? BECAUSE THEY PERFORM BETTER!!
are you that dam ignorant? Your running your mouth off without actual knowledge trying to get green squares from people for your "knowledge" that you post false information. FUCK YOUR "knowledge" your post above proves you just think you know what your talking about. And actually have had no experience running high performance rotors or pads. Your buddy this.. have him post from his experience. I will gladly"waste my money" on cross drilled rotors and have less stopping distance/greater stopping power every time i need brakes.

back to topic,
good luck man, I would think you really have something loose on your front end, or have a separated tire, wheel out of balance, or something. I doubt that your caliper is the culprit, but it is possible.

relax. you want to debate this make another thread.

alot of people run $20 blanks on the track and do fine
alot more people run $20 blanks on the street and brake without 'violent shaking'

what does that mean? it means it really has nothing to do with the op's problem and this discussion should be kept out of the thread

and for the record, i really don't care about green squares

[projectRDM]

last time i checked.. checker/kragen carries raybestos..

you ever felt the difference between a cheap blank rotor, and a high quality drilled rotor? Why the fuck do you think evo's, sti's, benz, bmw, etc.., etc.., etc.. run drilled rotors? BECAUSE THEY PERFORM BETTER!!
are you that dam ignorant? Your running your mouth off without actual knowledge trying to get green squares from people for your "knowledge" that you post false information. FUCK YOUR "knowledge" your post above proves you just think you know what your talking about. And actually have had no experience running high performance rotors or pads. Your buddy this.. have him post from his experience. I will gladly"waste my money" on cross drilled rotors and have less stopping distance/greater stopping power every time i need brakes.

back to topic,
good luck man, I would think you really have something loose on your front end, or have a separated tire, wheel out of balance, or something. I doubt that your caliper is the culprit, but it is possible.

Please kid, you're digging a HUGE hole. Why do F1 cars run SOLID rotors? Hmmm. Heat dissipation, simply put. More mass can withstand more heat. You know why manufacturers drill rotors? Looks, that's it. You think you're getting a better performing product so you pay the money. A properly built vehicle doesn't need cross drilling to cool the rotors, the vehicle itself directs airflow as needed to do it.

[bbejj123]

did you bed your brakes properly? or did u even do it? i know a lot of people who just slap new ones on and didnt even bed them and the same thing happened...they ended up warping their rotors =/

[opponheimer]

A rotor is a rotor. If it's cut on a straight lathe, I could give a fuck if it costs $5, it's a straight rotor. This nonsense about having to buy $100 rotors with pretty vanes and holes is absolutely stupid. Get that shit out of your head. I buy NAPA blank rotors and have for over 15 years, never had an issue with warping unless I boil the fuckers on a track. ANY rotor will do that. Additionally, a properly maintained car, even with 'POS' rotors will rarely ever need to have them replaced unless they do warp or see damage from the pad's backing plates when worn too far.

I'm going to go out on a limb and suggest two possible culprits, pad knockback or a worn wheel bearing. Either of those would cause symptoms as described.


Can you describe pad knockback, and will a bare wheel bearing (if faulty) make noise when spinning by hand, or wobble? Mine does neither of these, it seems fine.

[aznpoopy]

if your wheel bearing is bad the wheel will tilt when you jerk it around while the corner is jacked up. an unbroken wheel bearing = wheel will be solid with absolutely zero play when you do this test.

knock back is a bit more involved to explain
luckily someone did it for us
check this link
http://www.stoptech.com/tech_info/wp_knockback.shtml

[projectRDM]

A bad wheel bearing will have play and make noise when turning freely by hand, but you'll need to pull the rotor to get right at it. The noise may not be present, or it may be very low and only be audible under load. Sometimes it's more noticeable under braking due to the increased load on the hub itself, just as the play would be more evident.

Pad knockback is less of a culprit here, but if the pads are wearing extremely uneven you can get a vibration as they seat against the rotor.

[opponheimer]

You know I just thought of something, the extended studs I have have really shitty knurls, and the studs just barely stay into the hubs. I'm curious if that could have anything to do with it?


I also still have the stock s14 auto brake master cylinder.. Which according to the StopTech site could be a cause of knockback...

[projectRDM]

Very possible, but you'd think the stud play would be more apparent not under braking. Still if they're moving at all you're introducing harmonics into the wheel somewhere.

[rps13drift]

last time i checked.. checker/kragen carries raybestos..

you ever felt the difference between a cheap blank rotor, and a high quality drilled rotor? Why the fuck do you think evo's, sti's, benz, bmw, etc.., etc.., etc.. run drilled rotors? BECAUSE THEY PERFORM BETTER!!
are you that dam ignorant? Your running your mouth off without actual knowledge trying to get green squares from people for your "knowledge" that you post false information. FUCK YOUR "knowledge" your post above proves you just think you know what your talking about. And actually have had no experience running high performance rotors or pads. Your buddy this.. have him post from his experience. I will gladly"waste my money" on cross drilled rotors and have less stopping distance/greater stopping power every time i need brakes.

back to topic,
good luck man, I would think you really have something loose on your front end, or have a separated tire, wheel out of balance, or something. I doubt that your caliper is the culprit, but it is possible.

So you like spending tons of money on brake rotors that crack easy? I personaly have tried them all drilled/slotted/oem and i never notice a difference. The only significant brake improvement i have ever noticed was from 1- bigger calipers 2- stainless brake lines.

[aznpoopy]

iirc the auto s14 bmc is 15/16" which is one of the 'proper' options to use for z32 brake conversions

[opponheimer]

Very possible, but you'd think the stud play would be more apparent not under braking. Still if they're moving at all you're introducing harmonics into the wheel somewhere.

Yeah. I tackwelded the back of each wheel stud to the back of the hub to allow no rotation or in/out movement. Ill play with my wheel bearings more thoroughly tomrorow evening

[Phlip]

I agree.. Pads is where you lay down the cash. $20 china built rotors are more prone to cracking. And thats why i wont use them on performance applications. Sure on a dd car with no mods.. ya i use the OE "cheap" rotors from Autozone or NAPA, but not when i am "agressively" driving.
Turning a .0090'' off of a rotor i doubt will weaken it..
But i am not going to argue this.. I have said my peace, You guys have said yours.
So the aggressive street driving, extensive autocrossing and (well, heh, I am in NC) 2 times I actually went to drift my old S14 on those same pads don't count as "aggressive"? Should I tell you now that the next ones to crack on me or warp outside of any fault of my own (e-brake while white-hot, etc...) will be the FIRST? Do you not get it yet? If YOU experience any major issue with them, then YOU are the problem, and hell, even when you are the problem, as long as you kept the receipt, then it is easier for them to just replace them than to argue with you about it.

[g6civcx]

My test data.. Lamborgini, Ferrari, Porsche, Bugatti, BMW, Corvette, Jaguar, Bentley, STi, Evo, Mercedez Benz, Viper, GT500, Landrover, Lotus.. need i go on? all of these companies would not put a drilled rotor on if it did not increase braking power and stopping distances. They have spent mega $ on R&D in this factor

You know why manufacturers drill rotors? Looks, that's it.

Do you have rebuttal evidence?


as has the F1 series, NASCAR, tons of NHRA teams, Brembo, Stillen, Wilwood, Project Mu..

Why do F1 cars run SOLID rotors? Hmmm. Heat dissipation, simply put. More mass can withstand more heat.

How about this one?




why do you think they cost $100+ a piece? Because they work! Sure they are overpriced. I wouldnt pay retail.. NO WAY! but my cousin works for Brembo, and i get project Mu real cheap..$60 each cheap. I am trying to gain access to alot more rotors so i can do a GB on them..

You think you're getting a better performing product so you pay the money. A properly built vehicle doesn't need cross drilling to cool the rotors, the vehicle itself directs airflow as needed to do it.

Why would i test stuff that PLENTY of companies have done that for me..?

Simple question. What is the purpose of crossdrilling?

[burnsauto]

Simple question. What is the purpose of crossdrilling?

To help get rid of the layer of gas that forms when the pads meet the rotor, and I've read "claims" about heat dissipation, but still question it personally.

Honestly, I'd go with blanks, better quality blanks...but still no cross drilling or slotted action going on. Cross drilled ones crack all the time and once that happens, there's nothing you can do about it but buy new rotors.

If you warp a blank, you at least have the option of cutting. Cutting a rotor isn't dangerous if done the correct way. Not much material is cut away, and the rotors are supposed to be measured to consider cutting anyway. If the person cutting the rotor knows what he/she is doing, you won't have to worry about the rotor failing or the piston over-extending.

but... just my 2¢

[g6civcx]

To help get rid of the layer of gas that forms when the pads meet the rotor, and I've read "claims" about heat dissipation, but still question it personally.

I agree with this.

Honestly, I'd go with blanks, better quality blanks...but still no cross drilling or slotted action going on. Cross drilled ones crack all the time and once that happens, there's nothing you can do about it but buy new rotors.

I also agree with this.


I'd still like to hear what sac has to say about my question.

[Daniel.]

I didn't know evo's had cross drilled rotors. but who am i kidding, i don't own one so i wouldn't know.

oh wait...

[projectRDM]

I'd still like to hear what sac has to say about my question.

He's busy having his ass handed to him on a platter over in premie land. He'll be back to nurse his wounds in a minute.

[g6civcx]

I didn't know evo's had cross drilled rotors. but who am i kidding, i don't own one so i wouldn't know.

oh wait...

I can tell you VIII and IX have solid discs.

[Daniel.]

I can tell you VIII and IX have solid discs.

and the evo registered to me parked in my driveway agrees with you.

[usdm180sx]

Rotors could be warped because of improper embedding. This article was really helpful: http://www.stoptech.com/tech_info/wp_bedintheory.shtml

[Rayne]

Rotors could be warped because of improper embedding. This article was really helpful: http://www.stoptech.com/tech_info/wp_bedintheory.shtml

You beat me to it.

[Silverbullet]

To help get rid of the layer of gas that forms when the pads meet the rotor, and I've read "claims" about heat dissipation, but still question it personally.



The gases are no longer present with the material used for modern day brake pads.

Slotted rotors may cool a little quicker for road racing with a lot of on and off braking, but you get less bite compared to a plain rotor since there is less contact.

For most people, plain rotors are the best bet, even for weekend track guys.

[babowc]

Oh NOEZ.
MAI ROT0RZ ARE GOING TO EXPL0D3$$!!

[Rayne]

actually, i was busy talking to my coach. (I play college baseball.)
but look at the evo X...
drilled rotors do dissipate heat better than solid discs. That is one of the reasons why high-line auto manufacturers go with them. Looks is another, But not the only reason.

I hate to break it to you, however the EVO X uses ventilated rotors on the front and rear brakes. Rather than cross drilled rotors. Do not confuse ventilated, solid, rotors with slotted rotors.
EVO X Specifications list. (http://www.mitsubishicars.com/MMNA/jsp/evo/08/specs.do?loc=en-us)

In some cases, due to poor manufacturing cross drilled rotors are known to crack at the holes over time. Anyway Russ and other members can share greater knowledge on the disadvantages of cross drilled rotors than I am able, for the time being.

[!Zar!]

and the evo registered to me parked in my driveway agrees with you.

My sti agrees with you also.

[g6civcx]

do not confuse ventilated, solid, rotors with slotted rotors.

You are correct. Ventilated = cooling vanes. Solid = nothing. slotted = slots on the braking surface, drill = same

I don't mean to pile on, but here's what Tire Rack has to say about Brembo:

http://www.tirerack.com/brakes/brakes.jsp?make=Brembo&model=Sport+Drilled+Rotor

Brembo Sport drilled brake rotors are designed to meet the challenges of high performance street driving while adding an authentic, race-ready look. NOTE: Light truck and SUV rotors with studs or bearings are uncoated.

NOTE: Brembo Sport drilled brake rotors are not recommended by The Tire Rack for track use or intended to be used in conjunction with race compound brake pads on the street. For severe duty brake demands see Brembo Sport slotted brake rotors.


IMPORTANT REMINDER: Slotted, drilled or dimpled rotors offered as OEM replacements should not be considered appropriate for high-speed track use.

While grooved, drilled and slotted rotors offer an enhanced appearance and add some resistance to the boundary layer of gasses that can build up between the pad and rotor, they are not designed to withstand the extreme temperatures that are produced on the racetrack. If they are used on the track, it is very important that the rotors be carefully inspected and should not be driven on if even minor signs of deterioration are seen. Note, too, that if any products are used on the track they are not warrantable.

[burnsauto]

The gases are no longer present with the material used for modern day brake pads.

Slotted rotors may cool a little quicker for road racing with a lot of on and off braking, but you get less bite compared to a plain rotor since there is less contact.

For most people, plain rotors are the best bet, even for weekend track guys.

have any proof that the gases are no longer there? im not being a dick, im genuinely curious.

[Dream240]

wow....haven't seen a thread like this in a while.

The poor OP has just gotten lost in this mess.

To help you out OP:

Things to check out,

Front tension rods having blown bushings (do you hear any clunking coming from the front when you brake?)

Do you have a dial indicator? if so use it to check the rotor surface for the actual warped reading. How bad are they?

Have you checked all your front suspension bolts for a loose gremlin? You might have a loose bolt on the strut, front LCA, hub locking bolt, etc. Check everywhere.

How's your pad wear? are they new? how many miles? enough miles to notice any wear indicators? Look for uneven thickness from the inside pad related to the outside pad. This can tell stories about your calipers.

If you're getting a continual warped rotor regardless of how many times your turning them, then you have an overheating problem(since you cancelled out the over/uneven tightening lug mistake, which is VERY common). Which mainly comes from a locking/sticking caliper. It locks and causes the pads to just wear into your rotor. Will also help explain a wheel pull if you've been having that problem even after getting an alignment.

Hows your brake fluid? do you notice instances where you have to apply the brakes harder than other times? Hear any grinding at slow/moderate speeds coming from the brakes?

I know I'm asking alot of questions but all this stuff will help us find your problem. Unless of course you already solved it.

[heiyuu]

have any proof that the gases are no longer there? im not being a dick, im genuinely curious.

Ur not a dick. I didn't find this info out until last month lol.

http://en.wikibooks.org/wiki/Nissan_240SX_Performance_Modification/Brakes#Rotors

[burnsauto]

Ur not a dick. I didn't find this info out until last month lol.

http://en.wikibooks.org/wiki/Nissan_240SX_Performance_Modification/Brakes#Rotors

seeing as this thread is way off topic already.. and has been before i even started posting on it..

I looked at the link, and I see two small problems with it.

1. its on wikipedia.
2. They mention that even more developed race pads still produce a "finite" level of gas, meaning the gases have been limited with the newer semi metallic compounds they use today (as compared to the organic compounds of yesteryear). But, the gases are still present, in small amounts or not.

There are quite a bit of cars that roll off the assembly plant using organic pads though, granted they aren't the most high performing cars either. A drilled and/or slotted rotor has it's advantage, but they are far out-weighed by the disadvantages that come along with using them.

[johngriff]

As for the gas produced by braking, they are a bi-product heating and pressurizing petroleum products/ "organic material". I believe organic pads are still around, but these are the same pads that literally explode into chunks when pushed beyond the limit (i know first hand). With an eye towards racing you are looking at metallic, or carbon fiber, or Kevlar, or a blend, but want to stay away from the organic compounds.

Like has been said 100 times before in this thread, GOOD pads is no 1. For the most part, a bigger rotor, with a larger surface area will brake better because it can absorb more energy, and quickly dissipate more heat. Take material off the contact surface (from drilling or slotting) is only detrimental in both total surface area of contact and part stress limits.

And to the OP.

Did you change your wheels/tires when you did the brake upgrade? The majority of times I have had a shimmy/shake in the front it was because of un-balanced wheels.

[gotta240]

Will you fucking assholes quit spreading this bullshit knowledge about drilled and slotted rotors?!

I have 3 or 4 used sets i need to get rid of!!! SHHHHHHH!!!!

[landins13]

heat warped. plain and simple. if youre on stock rotors you need to roll into breaking or youll warp the rotors.

[MrChow]

Will you fucking assholes quit spreading this bullshit knowledge about drilled and slotted rotors?!

I have 3 or 4 used sets i need to get rid of!!! SHHHHHHH!!!! LOL!!! This thread is fun to read.

To the OP: Retraces your step. Everyone has posted answer here.

[tgd89]

Not to further the arguement, but the way I always had it explained to me was that drilling rotors was to release pent-up gasses from the pads, and slotting grinds off a bit of the pad surface in order to reduce pad fade.

To the op, I bought some brand new cheap rotors from NAPA and got shakes from them under hard braking. Turned out they were bad from the box, it happens.

[opponheimer]

To end topic it was one front left wheel hub.