Brake Pulsation

[Chris Talarico]

I have an 2003 ST with 58,000 miles on it.

The brakes have recently been pulsating alot, with lots of feedback in the brake peddle and steering wheel. Is it time to change my rotors? Most likely the front first?

I imagine around 50k and this will happen. Also does anyone actually torque down their lug nuts the the actual specs? would this warp rotors.



Thanks to all you ST gearheads in advance.:banana:

 

[TrainTrac]

Yep, sounds like your rotors are warped. Mine was doing the same thing. Did the brakes this past weekend, and the rotors were indeed warped. I was able to get them turned, though.



Brakes are much better now, pulsation/vibration is gone.:banana:

 

[Jerry Gerner 2]

yeah, I would say that it sounds like your rotors are warped. No torqueing the lug nuts to the spec'd torque won't warp the rotors. I have tightened the the lugs to the spec'd torque,and then tried to loosen them and didn't have real resistence so i tighten them with 4 star lug wrench, not the little ones they sale, can't get any leverage use the larger one. Another thing you might want to do is when you take truck to shop make sure they use the torque rod on the air gun or it can warp wheels, rotors and you won't be able to loosen the lug nuts when you need to by hand. Hopefully this helps you. I have a 2003 ST that I just replaced front/back rotors/pads and rear calipers, used AutoZone parts. Had cross dilled rotors on but they didn't last long and they aren't worth it in my opinion.

 

[Steve McKellop]

My name is Steve and I'm a torquer .........:unsure:



I torque the lug nuts EVERY time I change a wheel/tire on anything I own. Warped rotors will teach you that lesson. Now try this since it's FREE. Loosen your lug nuts and torque them to the factory or wheel manufacturers specs (add a few lbs if you don't like factory specs but I figure the engineers know best) Drive a few days and repeat. Drive a few more days and repeat again. I actually had a set of rotors on a Nissan 4x4 correct themselves almost completely by doing that. That's when I began torquing every time.

 

[Richard L]

Your rotors are either warped or the run-out is out of tolerances. The only way to know if you need new ones is the have them measured for wear and run-out to determine if there is enough meat left on them to turn them.



Most front rotors can be turned at least once as long as they are not gouged up too bad.



The Sport Trac seems to have the rotors that warp rather easily and frequently and typically do not have enough thickness left to turn them.



The main drawback to turning warped rotors is the fact that they tend to warp again rather quickly since the turned rotors are even thinner.



ncranchero is right about torquing the lug nuts, but I don't think you have to be that anal about it and torque them every week ??? The main point is that the lug nuts should not be installed with a pneumatic impact wrench, which is commonly used in most garages and tire shops. Insist that they tighten your lug nuts to factory specs using a torque wrench. I even had a tire shop tell me that they charge extra for torquing the lug nuts, but there was know charge if they used the impact wrench. Since he was just fixing a tire with a slow leak, i let him used the impact wrench and I loosened them and torqued them when I got home.



...Rich

 

[Steve McKellop]

.....but I don't think you have to be that anal about it and torque them every week ???

That's ok Rich, I've been called something close to anal before.........:lol:



You missed something there. I only loosened and re-torqued them 2 or 3 times in an attempt at un-warping the rotors. It worked surprisingly well. Took almost all of the warp/pulsation out. If they are heat warped from excessive/severe braking the only thing that will help is new rotors.

 

[Richard L]

ncranchero,

Sorry, but i did not "Call" you anal. I only implied that your actions of retorquing your lug nuts every week was somewhat anal. But if you were offended, I appologize, that was not my intent to imply that you were anal, only that your retorquing was anal.



I know that using a torque wrench to tighten the can lead to warped rotors, I simply don't beleive you can "Unwarp" rotors by simple retorquing them. It's possible that if your tires were recently installed with an impact wrench, they may have distorded the rotors and your quick action in retorquing prevented to the rotors from warping.



Or perhaps your rotors were not installed correctly, meaning that there was some debris or rust on the axle flange or the back of the rotor hat that kept the rotors from bolting down perfectly flat and did not let the rotor run true. When you removed or loosened the rotors to retorque them, you either brushed of that small amount of debris, or it simply fell off and that allowed to rotor to run true.



Once a rotor truely warps, you are not going to correct the problem by properly torquing the lug nuts. The damage has been done and no amount of retorquing will fix that. The rotor must be trued up with a lathe or replaced.



...Richard

 

[Steve McKellop]

That's ok Rich, I've been called something close to anal before.........

That was a pun ... joke ... funny .... jest .... see the little laughing green guy? No apology needed.

You missed something there. I only loosened and re-torqued them 2 or 3 times in an attempt at un-warping the rotors.

I don't re-torque my lug nuts every week(see above). I did that several times in an effort to un-warp some rotors on a weekend mud buggy. Whether you believe it helped or not is up to you. I know what it did.

Or perhaps your rotors were not installed correctly, meaning that there was some debris or rust on the axle flange or the back of the rotor hat that kept the rotors from bolting down perfectly flat and did not let the rotor run true. When you removed or loosened the rotors to retorque them, you either brushed of that small amount of debris, or it simply fell off and that allowed to rotor to run true.

Good theory. May be the case somewhere, sometime ........... not this time.

I know that using a torque wrench to tighten the can lead to warped rotors,

Torquing lugs can warp rotors????? I know I must be misunderstanding that......



Rich we don't seem to be understanding each other here. We can agree to disagree and have peace.



I know I'm a newb and totally unproven here. Just for kicks and giggles I'll give a brief summary of my limited qualifications. I'm 54 years old, been mechanic-ing since I was 14, spent 35 years in the vehicle/fleet maintenance field, hold a card full of current ASE certifications .........I surely don't know everything but I'm not new to a pair of pliers.:huh: Everyone is entitled to their own opinion, I respect yours. Insinuating I don't have a clue as to what I'm talking about is a bit invalid. Peace brother.



BTW, nice Benz!

 

[jason vocaty]

can we leave Todd out of this thread please he has enough jibberish to deal with!

 

[Steve McKellop]

Nobody's talking about Todd .......... he's a great guy!!!!:banana:



( spoken in my best kiss-up voice )

 

[Richard L]

ncranchero,

No offense taken and yes we can disagree without insulting each other. My main objection is that there is no logical theory behind why retorquing the lug nuts serveral times would unwarp the rotors if they were truely warped. That's why I said that if one or more of the tires were removed and then installed with an impact wrench, it may have distorted the rotor enough to cause the symptoms of a warped rotor. Simply retorquing them to the proper toque may have released that distortion before the heating and cooling of the brakes had time to permanetly warp the rotors.



Often times people do things that fix problems, and the problems go away, but not for the reason they think. That's why I stress that problems need to be diagnosed so you know exactly what problem you are trying to fix. If the run-out was not measured and the rotor was not measured with a micrometer, you cannot say that the rotor was warped, only that you suspected that it was warped. Over torquing the lug nuts can cause warped rotors, and proper torquing can prevent premature warping, but once warped, retorqing cannot correct a warped rotor.



I do agree that proper torquing is important and if the lugs were not overtightened for too long, you might try correcting the torque and prevent the permanent warping.



Still friends, no insults and I respect your input and your opinion. I just don't agree with it.



And thanks for noticing the Benz.



....Richard

 

[Steve McKellop]

No offense taken and yes we can disagree without insulting each other

As it should be!





I learned a long time ago that some things defy logical explanation. I've even proven a few points to one of my hard headed buddies that has degrees out the ying-yang Yes I loved it!



Good deal Rich ..... carry on Friend!