Sounds like uneven pad deposits on the rotors. Try bedding the pads in correctly per the pad manufacturer's guidance. Also verify your lugs are torqued correctly.
Steering wheel shaking while applying brakes around 60 mph.
I need help figuring out my little problem. I put aftermarket drilled/slotted rotors on the front of my '08 Sti, along with fresh pads this past may. My issue is when I'm driving at around 60 mph, and apply the brakes somewhat hard, the steering wheel shakes violently. But it doesn't happen at any other speed. Please help!!!
1 - 20 of 37 Posts
could also be warped rotors, or wheel a wheel bearing could be going out, if the bedding in of the pads and tighting the lugs dont help
Agree with both of these guys mostly. But chances are, warped rotors. A lot of suppliers will stack them in stock and they can warp up. Did you make sure the pad seats were clean and mildly lubricated with anti-seize? When applying the brakes the pads slide. If they bind it could/can cause issues.
Sounds like a brake pulsation to me. If the brake rotors have been overheated they're likely warped which will cause the issue you are describing.
What brand of rotors did you get? Quality rotors are difficult to warp, not impossible but difficult.
Hawk has good instructions for how to bed/re-bed your pads. Give that a try first as its easy/fun and free.
Hawk has good instructions for how to bed/re-bed your pads. Give that a try first as its easy/fun and free.
I had the same exact problem. Replaced the rotors and the problem continued. Ended up being a bad tie rod end.
Just go to an alignment or brake shop and have them check your rotors for any warping. Whatever it is, get it fixed asap as driving on warped rotors can be dangerous and can lead to damaging the calipers.
Wrapped rotors. It has to do with the thermal expansion and retraction of the metals in the rotor as they are used. With the fall and winter coming upon us it usually brings rain which once splashed on hot rotors under breaking will cause them to cool down as a rapid pace, thus causing the warping of the rotors. Get them turned if they are within spec (need at least .0030 of an inch above the minimal number cast into the rotors) otherwise get new rotors.
Get it fixed ASAP. Could be a bad tread in your tire, a warped rotor, bad brake pad, or a a problem with your alignment/balance.
I have had this issue on other cars. The first time it was from a bad tread on a tire (that I had abused to that point), the second time it was from the brake pads themselves: I couldnt see a problem, but I changed them anyway because I didnt want to bring the rotors to a shop to be cut or buy new ones. I guess I was lucky that fixed the issue. Hope this helps.
I have had this issue on other cars. The first time it was from a bad tread on a tire (that I had abused to that point), the second time it was from the brake pads themselves: I couldnt see a problem, but I changed them anyway because I didnt want to bring the rotors to a shop to be cut or buy new ones. I guess I was lucky that fixed the issue. Hope this helps.
Though all the suggestions here are possibilities. Mine did this and was it one of the motivations for doing rotors and pads. Been fine since. Guess I checked that noting was loose first. My rotors had really larges shoulders for over a year so I was prepared. If your doing them read up on Timeserting them. You can find heli-coil type inserts easy enough if you don't buy Timeserts ahead of time. A front and a rear (2 of 8) calipers had to be rethreaded. I would try not drilling them I were to do them again, and if that worked I would Timersert them all. Oh, get the bolts to remove the rotors too.
I dont think driving in the rain can cause rotor warping, especially since the rotor would be spinning, and cooling across the whole rotor evenly, aka no un-even cooling.Wrapped rotors. It has to do with the thermal expansion and retraction of the metals in the rotor as they are used. With the fall and winter coming upon us it usually brings rain which once splashed on hot rotors under breaking will cause them to cool down as a rapid pace, thus causing the warping of the rotors. Get them turned if they are within spec (need at least .0030 of an inch above the minimal number cast into the rotors) otherwise get new rotors.
Parking your car with super hot brakes in one place for a long time will have the effect you are talking about, but that is because of the brake pads and caliper being hot and cooking one spot on the rotor and not the rest... (mind you, im not talking daily-driving hot, im talking track-day hot). Even in this scenario, its not guaranteed to warp anything.
You may also need to clean the brake deposits in the caliper. Had a guy whos caliper wouldnt mount up perfectly because of this and it caused uneven brake force to be applied. Just another tip.
...and pulsating like this is usually caused by a warped rotor. What happens is, you hit the brakes, the ABS gets thrown off due to the warped rotor, then the pistons in the calipers have a hard time retracting quick enough. The warp basically jams the pistons back in very quickly, the pistons get jammed and this eventually will create gouges/rings/imperfections in the caliper shaft where the pistons live. Once this happens, your calipers are toast. I strongly recommend you take the calipers off, pull the pistons out (ALL of them), and inspect. If the caliper shafts are still smooth (and the pistons have no sign of damage..all it takes is a tiny nick or something), get a piston seal rebuild kit and put back together. If you simply replace the warped rotors without inspecting the caliper shafts you will end up with more warped rotors once again because the pistons will still be binding again, and as a result, will cook the rotors and warp them. Trust me on this one, I've been through it on a couple different cars. Most people simply replace a warped rotor and fail to inspect the caliper shaft for damage. Its an endless loop unless you address EVERYTHING properly.Sounds like a brake pulsation to me. If the brake rotors have been overheated they're likely warped which will cause the issue you are describing.
Never once in my post did I mention a rain drop. I said rain. And yes I do know what I'm talking about as I did brakes and suspension for 3+ years as a living. And we saw more people complaining about warped rotors in the fall and winter when the rain came. And your rotors can heat up substantially in city driving so your theory is trumped.
Guys let's not start a flame war over thermodynamics. I'm sure we can all agree that when it rains, puddles can, and will, form. And we can all agree that a puddle has a much larger capacity to cool down a brake rotor than a couple pf rain drops. It's therefore pretty likely that if you hit a puddle at the bottom of a hill or after a couple of hard braking events your hot brake rotors is going to get doused. Now unless the water from this puddle manages to hit all surfaces of the rotor, inside and out, then the rotor is going to cool unevenly. Furthermore, the center of the brake rotor is mated to the hub on the inside and the wheel flange on the outside which means that in all likelihood the center of the hub is going to stay warm longer than the exposed braking surface. This explains why many more customers come in during rainy season complaining of brake pulsations.Sticking to your guns I see. I'm not doubting the complaints, I'm telling you the physics of heat transfer. The amount of energy that rain drops can absorb from a hot cast iron brake rotor is negligible (unless your driving through standing water...). It's a concept known as thermal mass or thermal inertia. Put it to you this way, if a go kart and a Semi get in a head on collision, how much is the Semi going to slow down?
And like I said, even if your rain water cooling could suddenly cool off the rotor as you suggested, the rotor is spinning and would cool evenly, thus no warping.
If you need a book to tell you how something works that's your thing.If you need, I can break out my heat transfer book and show you the math...
I'm making the statement from experience, not a theory. Having done more brake jobs in one day than the average person will in a lifetime and more in a week than the average car guy will in his life. I think my first hand experience has more than just quoting a book behind it to stand on.
And it looks like you're sticking to the whole thing that I said "rain drop" which once again I never said. So until you are able to accurately challenge my experience, your challange that rain/rain water/water has nothing to do with warping rotors is moot.
It however seems that the person posting below you grasps what I said.
That's it, I'm not driving in the rain anymore. 
Guys, I said rain drops, because that's what rain is. Water on the ground is puddles. Water splashed up is also in the form of drops.If you need a book to tell you how something works that's your thing.
I'm making the statement from experience, not a theory. Having done more brake jobs in one day than the average person will in a lifetime and more in a week than the average car guy will in his life. I think my first hand experience has more than just quoting a book behind it to stand on.
And it looks like you're sticking to the whole thing that I said "rain drop" which once again I never said. So until you are able to accurately challenge my experience, your challange that rain/rain water/water has nothing to do with warping rotors is moot.
It however seems that the person posting below you grasps what I said.
I'm stating that your rotors, while driving, will not get wet enough to cause drastic cooling, and that since the rotors are spinning, the whole rotor gets wet, not just a peice. The rotors will cool off in the rain, yes, but not as you are describing. They will cool evenly and not instantly as you seem to think.
If what you say is true, how come I've driven in the rain for years without my rotors warping?
Blue scooby has a point.
From an engineering perspective, the water analogy does not make much sense, as water splashing up on the brake disc would quickly dissipate around the rotor which is turning quickly. At lower speeds, braking friction/force is much less so we do not need to consider low speed braking in the situation.
Another example to prove the point about water being less valid; since we have concluded that the water will quickly be evenly distributed around the entire disc, we can assume that the 'cooling' effect will be on the disc as a whole. Now, with that, consider this; does colder (winter) weather cause discs to warp? not any more than normal weather. But it has a similar (if not worse) effect on the cooling of a brake disc since the ambient temperature of the air around the disc is much cooler than the brake disc itself (same effect as water).
Cheap brake discs can experience warping under lots of heavy braking. Was somewhat common on cobalts. Mine never had this issue past 100k kilometers of driving, and I had some heavy braking situations. But even still, it is not as easy as it seems. For our OEM discs to warp like that, well, as stated before, good quality discs CAN warp but it is quite hard to do.
From an engineering perspective, the water analogy does not make much sense, as water splashing up on the brake disc would quickly dissipate around the rotor which is turning quickly. At lower speeds, braking friction/force is much less so we do not need to consider low speed braking in the situation.
Another example to prove the point about water being less valid; since we have concluded that the water will quickly be evenly distributed around the entire disc, we can assume that the 'cooling' effect will be on the disc as a whole. Now, with that, consider this; does colder (winter) weather cause discs to warp? not any more than normal weather. But it has a similar (if not worse) effect on the cooling of a brake disc since the ambient temperature of the air around the disc is much cooler than the brake disc itself (same effect as water).
Cheap brake discs can experience warping under lots of heavy braking. Was somewhat common on cobalts. Mine never had this issue past 100k kilometers of driving, and I had some heavy braking situations. But even still, it is not as easy as it seems. For our OEM discs to warp like that, well, as stated before, good quality discs CAN warp but it is quite hard to do.
1 - 20 of 37 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
IW STi Forum
A forum community dedicated to Subaru Impreza and STI owners and enthusiasts. Come join the discussion about performance, engine builds, exhaust, modifications, troubleshooting, maintenance, and more!
Full Forum Listing
Recommended Communities
