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Discussion Starter · #1 ·
Does anyone know how to check yourself if you have rotors warped. I guess I could put the car on jacks and spins the rotors but would anyone know different ways?


I'm so frustrated with these brakes I can't get them to work properly :mad:
Since I changed rotors and pads the brakes don't feel great and the dealer did not find anything wrong a few weeks ago. Now, I'm getting some vibrations while driving at higher speed and definitely more so while braking though it doesn't do it at super slow speed nor when I brake hard.
The car was balanced and aligned not long ago.

I'm wondering if it could be something else more suspension/steering oriented...
I just had the axle changed and it cost me a load of money. I would just like the car to feel right dam it! . . .

And to make the matter worse I just crapped one of the rims tonight. Harrrrrr...
It's just on the outer edge part and not too deep so I hope I'll find a spray can color that matches and can fix it without seeing it too much.

sorry for the ranting . . .
 

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warped rotors are felt thru the brake pedal pulsing

un balanced tires are felt thru the steering wheel shaking at speed. usually around 60+ mph

unbalanced tires can get out of round and with rebalancing does not "fix" the tire being out of round. thus the shaking will be there in the steering wheel.

where are the OEM wheels? put them on and see if the vibrations go away. 225/40/18 are skinny and prone to bent wheels.
 

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Discussion Starter · #3 ·
Thanks for the quick reply,

Good idea about the OEM wheels. I should have thought of that.
To be honest I don't know at the moment if it was pulsating through the brake pedal or not. It was definitely through the steering wheel especially while braking.
I have not hit anything so I'd be shocked if my wheels were out of round but maybe one of the balancing weight came off. I'll check for that too tomorrow.

It looks like I'm in for another put the wheels off and on session again...
I was going to change my rear pads anyway and clean the brake again to see if accidental grease could give me bad brake results.
I have those EBC slotted rotors. I'm questioning the quality of those or the slotted part as well now. I feel I should have got plain smooth rotors...
 

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Wobbles or pulsing won't happen unless your braking with warped rotors. Trust me you'll know if your rotors are warped your brake pedal will pulse. If you still want to investigate further then go to harbor freight and get a magnetic dial indicator and see the runout of your rotors
 

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Discussion Starter · #5 ·
Yeah, that's probably what it is... That's why I asked in the first place I guess so my hunch is probably correct... Sigh...
 

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Don't be too quick to blame warped rotors. First read this: Warped Rotor Myth. Does any of this ring true?
Also, be SURE to check your suspension condition. Specifically the control arm bushings & tie rod ends. I have cured countless "warped rotors" by replacing worn control arm bushings on a wide variety of European cars.
 

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when my rotors were "warped" along with pedal, my steering wheel s was shaking under harder braking as well
 

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Discussion Starter · #8 ·
Don't be too quick to blame warped rotors. First read this: Warped Rotor Myth. Does any of this ring true?
Also, be SURE to check your suspension condition. Specifically the control arm bushings & tie rod ends. I have cured countless "warped rotors" by replacing worn control arm bushings on a wide variety of European cars.
This is GOOD.
I'm going to check all I can tomorrow if weather permits! Now that you mentioned tie rod ends I'm thinking that it's not the first time have brake over some rough surface with wheels slightly turn and have the feeling the wheels are going to fall off. I'm not making any conclusions here but hmmm this all certainly makes me think twice here.
We'll se what I can find.

BTW, all these parts being heavy how do you tell if your control arm bushings or tie rod ends have a wear issue.
Also is it possible at all wheel bearings can cause vibration. I doubt it's that because it is a pulsating feel but I've said twice to my garage that I here this very low volume humming sound when pulling out of the driveway like the sound of a rusted ball bearing...
 

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I jsut dealt with this.

bad rotors up front will be in steering wheel., I honestly felt nothing in the brake pedal. Over mountain passes my steering wheel would shake violently.
Rear rotors will feel in brake pedal. I had just done rear slotted rotors so mine were good.

secondly. bad front rotors will destroy lower control arm bushing, and mine did. I would say visually look at the rear bushing for any cracks or if the arm is not centered in the bushing anymore. If its bad it may feel like bad rotors when braking. you may also get shaking at speed.
 

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This is GOOD.
I'm going to check all I can tomorrow if weather permits! Now that you mentioned tie rod ends I'm thinking that it's not the first time have brake over some rough surface with wheels slightly turn and have the feeling the wheels are going to fall off. I'm not making any conclusions here but hmmm this all certainly makes me think twice here.
We'll se what I can find.

BTW, all these parts being heavy how do you tell if your control arm bushings or tie rod ends have a wear issue.


Also is it possible at all wheel bearings can cause vibration. I doubt it's that because it is a pulsating feel but I've said twice to my garage that I here this very low volume humming sound when pulling out of the driveway like the sound of a rusted ball bearing...
Hit rod ends with rubber mallet and look for movement or sounds. wheel bearing shouldnt cause pulsing. jack up car and rotate wheel. if it wobbles its bad. but if it was bad you have awful driving 100% not just when braking
 

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Discussion Starter · #11 · (Edited)
Update:

So today I put the car on jack stands and cleaned all 4 brake sides. I also replaced Akebono Ceramic rear brake pads with Hawk HPS, same I have on the front.

It is too soon to tell if all is solved but I found a few things:

First this video shows what my passenger front disk brake sounded before I went to clean it.
It's hard to hear it so you'll have to turn-up the volume way up. Don't forget to put it back down afterwards :p
Also don't pay attention to the transmission gear noises. Just the brake noise. As you can see the pads would not ride evenly on the disc.



I removed all wheels and cleaned the brakes with quite a lot of brake cleaner.
I noticed that the inner hub-centric ring spacer on that wheel wasn't quite well positioned.
It's possible the rotor was out of alignment.

I swapped the front wheels with the rears just in case and put everything back as well as I could.
The rotors did not make the sound after that when turning by hand.
I'm hopping this could be what caused the vibrations with the edge of the pads knocking on the edge of the rotor slots.
I haven't done any highway driving yet to confirm vibrations are gone. So I'll cross my finger for the time being...


Secondly:
I replaced my rear pads with Hawk HPS.

I found on the back side of the rear left rotor a piece of metal or likely brake pad material that had bonded to the rotor. A very small piece but it would spin and created a uneven groove in the pad.
I should have taken a picture of the rotor but all I have are pictures of the pads.





I don't think those rear pads had much bite at all with that piece leaving with mostly 3 brakes out of 4! This has probably been some of the cause of my poor braking performance.
I took a very sharp knife and scrapped off the bonded material. The rotors where still very smooth under.

I still put the Hawk HPS on and after doing some of the proper sitting procedure I seem to have better brakes! But I'll have to see in the coming days to confirm since pads are never great initially.


If brakes confirms to be much better I would have learned two things:

1. Don't use two different pad compounds between rear and front. This likely creates a bad front/rear bias with different initial bite. I thought I would do that to dramatically reduce dust but I think that was a BAD idea.

2. Don't use Akebono ceramic pads with slotted rotors. I believe the combination of both slots on the rotors and slots on the pad caused some pad material to pill off which bounded to the rotor and made a poor braking.


I feel a little bit better now though I need more days to get a feel for it.
However I could tell right away that my hand brake was tighter (much more like it use to be)
Hopefully I'll be satisfied in the coming days. If not I'll have to keep searching...
AND btw, it seems my tie rods and bushings are okay.
 

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Discussion Starter · #12 ·
So brake performance is taken care of. YES!!!!

Now after the work I still have some slight vibration through the steering wheel to hunt.
For some reason it is about half what it was but definitely there.
No vibration felt through the brake pedal.

All I did is:
dismount all wheels.
Clean front brakes
Clean and install new pads on rear brakes
Check rotors for positioning (but I did not remove calippers for that so I don't know if something could be stuck behind and create bad sitting.
Swapped front and rear wheels
Remount wheels and tighten all very carefully and progressively

What conclusion can I draw from this?
- Wheel balancing is probably not the issue
- Issue with rotors uncertain
- Issue with suspension uncertain

I'm still suspicious it is not from the rotors because they seem to rotate well. I'll have to recheck that again though . . .

Unfortunately after the video I did not pay attention to the left side of the suspension so I'll have to recheck that as well . . .
 

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Likely pad deposits on the rotors due to those pads, seems after cleaning and new pads the problem was corrected? Which if that's the case then possibly the fresh friction material created a fresh biting surface.
 

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Discussion Starter · #14 ·
Likely pad deposits on the rotors due to those pads, seems after cleaning and new pads the problem was corrected? Which if that's the case then possibly the fresh friction material created a fresh biting surface.
Are you suggesting the vibration through the steering wheel could come from the rear pads?
I did not change the front. Just cleaned the rotors.
I don't know, I'm just asking... and I'm open to any suggestions here :)
 

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Oh, gotcha. No, steering wheel shimmy would be from the front brakes. However, "warped" rotors is generally a case of pad deposits built up on the rotor face which gives them an uneven runout and thus vibration. Cleaning or scuffing the rotor surface and rebedding the pads can fix this and/or resurfacing rotors which is most common.
 

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Discussion Starter · #16 · (Edited)
BTW kyle I think this is a new way to look at rotor vibration (at least to me but I would imagine that not too many people realize what can happen) and from seeing what happened to one of my rear rotor I'm glad you mentioned it! Pad material can really deposit on the surface of the rotor and make a mess as I tried to explained below.
Now I did not considered it in on the front and I should. That will be part of what I'll check next for sure!

Scuffing, hmm how do you do that?
I'd hate having to machine practically brand new rotors...

I think what I'll do is try to setup some kind of jigs to check the planar surface of the rotors. That I can do :D


Oh and additionally I'm just realizing that I bedded my new rear pads by following Hawk's suggested bedding procedure. I wonder if that is why in fact I get less vibrations than prior doing the work. It may have re-bedded partially the front as well! hmmmm...
 

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Pad deposits can be removed with specific braking procedures too, much like Hawks bedding procedure which works quite well. My Heico kit started to shimmy after a hard two hour drive over the pass, it has since cleared up after some simple stopping cycles.
 

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Discussion Starter · #18 ·

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Are you suggesting the vibration through the steering wheel could come from the rear pads?
I did not change the front. Just cleaned the rotors.
I don't know, I'm just asking... and I'm open to any suggestions here :)
You just happen to have more then 1 issue : 1. First - the Brake Tech @ Dealer could have missed a Speck of Dirt / Rust/ Crap - that's all it takes .
001 and It will screw with Your Rotors . ( Dirty Hubs )

2. The Other is Poor ( Old ) Brake Fluid - it will Not retract the Pads as Far - so a slight increase in Dragging Builds Heat on - One - side more then the other .

3. It just a lousy set of Rotors and Now they starting to Warp .

Dial Indicator - on the end of a Magnetic Holder . TOOLS can be borrowed from some - Auto Zones
 

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Discussion Starter · #20 ·
Thanks EngTehc,

2. not likely. I bled the brakes myself and after lack of result I asked my dealer for a brake fluid flush.

3. I don't think this is likely. I did do a few pad bedding procedure but overall the rotors are brand new. There are the front ones and thus much more rigid. I seriously doubt the rotors have "warp". It is not as if I raced with them and they got super hot.


So I tend to believe it has more to do with surface unevenness or bad sitting. I'm going to have to take these open for the fourth time.
Quick question: are the two front wheel free to spin from each other if the car is put on neutral. What makes it long is when I need to put the car on 4 jacks. If I can just lift one side at a time it's a bit faster but I need to be able to spin the front wheels...


I am getting a little paranoid now because other than my steering wheel vibrating when I brake at higher speed (and mostly at higher speed >40mph at least or in the mid range braking pressure) I'm getting some strange pulsating noise when the car is plainly rolling (no brake pressure applied). It does not move the steering wheel but I can here pulsating noise increasing or decreasing speed with my driving speed. It gets louder I think if I increase the speed. So I have something that does not spin evenly. It may still very well be brake related but since I had my axle replaced not long ago I'm getting concerned. It is also very regular which tells me it is not likely bushings or tie rod related I would assume.
 
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