Nooooo vibration in the Rotors
 

It's been only about a year and 15,000 miles since I've put on my slotted and dimple drilled rotors.

Right now I'm getting a really bad vibration so I'm coming to the conclusion that I warped my rotors. I dont think I bedded the pads properly.

Also after long drives often I would let the car sit a few minutes and wash the car. I'm assuming the hot brakes + cold water weren't too good for it.

Any chance that getting new pads and bedding them properly will solve this? :(

Did you torque the lug nuts so that they have even pressure? I would doubt that washing the car would have made them warp. I would look at the brake pads or how the calipers are working. :)

I pretty much re-did the whole brake system: remanufactured calipers, rotors, lines and pads all the way around.

Lugs are torqued to 90 ft lbs.

Fluid was just bled again.


It would stink to have to replace the rotors... they still look relatively new!

Tim, if you have recently had a puncture fixed, or a wheel balanced, you often find the garage will torque on the wheel improperly using the air tool and sequentially tightening each lugnut. They should only be tightened in the sequence 1-3-5-2-4.
Also, they should be hand tightened in the air first, then the car lowered, and finish tightened in the same sequence.

If you are hauling it up hard from high speed, you might well have warped them again, likely the front if anything. If there is a way you can get the car jacked up, spinning the wheels with a friend to help will show which rotor is warped. Spin the wheel, apply the brake very easy, and if it is warped, it will possibly catch and let go once or twice on every turn. If it's pulling even, the rotors are not warped.

Now if you find doing this that one or more of your rotors have warped, and if they look nearly new as you say, then you should consider having the rotor "shaved" dynamically at a machine shop.

I got that done very cheaply for mine and it was a success.

Joe:)

Or if you have been braking lightly for some time deposits can build up (depending on brand of pads). Try a couple of hard stops, works sometimes.

Hmmm, I recently had the tires changed a few months ago but I re-torqued them myself.

I thought you couldn't get slotted/dimple driled rotors resurfaced?

I will try getting the car up in the air and test it by spinning the tires

hey i have the same thing. did the same thing everything new but it alone happend when i'm braking. it has being about one year i think agin or take a mouth

Did you guys make sure that the mating areas of the hub and the rotors/discs, were completely clean and smooth before fitting the replacement components? It takes very little hard material to form an obstruction and put things out of true.

In affect the wheel/lug nuts comprise the attachment for both the wheel and disc/rotor to the hub. This arrangement is common and not restricted to the SVX. However somehow the SVX has been deemed to be in some way specially sensitive in respect of wheel/lug nut tightening torque.

This theory has been questioned by our most reliable practical authority, and I too can find no reason for this being applied as a particular negative against the SVX. Any car, and there are many, will have problems if there is hard foreign material obstructing the mating faces, or the nuts have been grossly badly tightened. :p

Brake vibration does not inevitably indicate warped discs. It's just a symptom, but that alone is not enough information to perform any kind of diagnosis.

If you went to your doctor complaining of a headache and he immediately told you that you had a brain tumour, without performing any other tests, I suspect you would not be very happy.

It's very easy to check for a warped disc, a garage would use a dial gauge, but any idiot can hold a pencil or even a fingernail, braced against the brake caliper whilst the disk is rotated, to see if there is any detectable degree of warpage, at the same time you should be looking for any variation of wear pattern or colour too.

While the wheel was off, you would be eyeballing any other components to see if they were bent, broken or even merely suspicious looking. You'd give things a damn good shaking too, looking and listening and feeling for any signs of free-play.

You'd look at the caliper to check that the bits that should move can move, and the bits that shouldn't move can't. You'd even be suspicious of the wheel and tyre.

It's a bit like being a detective, round up all the suspects, interrogate them all, identify the innocent and eliminate them from further investigation.

If you are not sure, do some more testing.

Finally, whilst you are looking you might find something else you need to fix :eek:

I would say check the tire pressure in all the tires. I had one tire off when i got it, all were 30-32lbs except front driver side, at 58lbs:eek: :eek: Needless to say it vibrated to hell when i tried to brake.

Ah, that's a highish torque isn't it? Specs say 72-87. I know it's not much extra though....
I know it's been said before, but it really is important to torque those nuts up properly - sounds like you're already doing that though. I go to 75, and even that is pretty hard when undoing them with a lug nut cross-bar.

Do the rotors have pad imprints on them? If so you might be out of luck. It is possible to straighten the rotors out and get rid of the wobble - I've done it myself, just by heating them up gradually to HOT and then cooling down gradually. Do what Trevor said and check the rotor/hub mating surface, you may find a bit of corrosion or something.

One thing definitely worth trying (already mentioned I think) is with new pads:
Check all the nut torques.
Make sure the calipers are sliding properly on the pins.
Then go driving - Start doing braking stops from about 60 mph to about 10mph (Don't stop completely). Increase the severity slowly until you are just above the abs level. Things should be a little bit smelly and HOT about now. Then keep driving doing some gentle stops so that everything cools down slowly. When you've cooled everything down you can stop completely. You'll know by then if it has worked or not anyway. Re torque all the nuts.

Matt

Well I got all my done a shop and it was not doing that till about ending of last year. Like it sounds like a tapping sound. Or it would be like if I had cards in a ridding bike wheel. That is what people said it sounds like. Anyone know what that may be?

CrazyPolo95
If you have drilled/slotted rotors this sound is completely normal. All it is is the sound of the air moving through the holes. When you hit the brakes it restricts air flow when each hole it sliding between the pads and when they open to the air again it is alowed to flow back through...So it is absolutely NOTHING wrong with your brakes