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Twizzler
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Discussion Starter #1
Last week I replaced all my rotors and pads and flushed the fluid from the brakes, everything went fine no probs, simple task...but I have found that my rear rotors are warped to the point that they contact the pads and squeek when rolling away from a cold start. Once the brakes are used the squeek goes away of course because its getting the brakes warm etc.. I did not use a torque wrench to put the wheels back on just a the Beetles lug bolt wrench, could I have warped them from overtightening?? I'm always trying to understand how a rotor can be warped from tightening lug bolts when the rotors mating surface is higher from the braking surface??? Advice please, do the rotors need to go in the garbage or is machining an option, they are all new oem from VW. Will loosening them release tension and allow them to be straighter or are they set up in this warped state permanently. Thanks all for any info.:confused:
 

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Twizzler
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447 Posts
Discussion Starter #2
Sorry I forgot to ask, what is the torque setting for the wheel bolts on the rears and the fronts?
 

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90ish for stock wheels, 70ish for aftermarket.

I picked up a torque wrench from harbor freight the other day for $16. It's cheap, probably too cheap; I dunno how accurate it is, but I know it's idea of 70lbs, is gonna be = to it's idea of 70lbs. (IE, it'll be even)

You seem to know your stuff, so I assume you did the star pattern and all that jazz. I don't know for sure what could be the problem. I know oem rotors don't take well to being resurfaced. Kinda like an M&M, they're hard on the outside, and soft on the inside. (I resurfaced once, after 10K you'd think they were about to rip off my calipers)

I'm having a time w/my front brakes too; sorry I can't help much. Be sure there's no rust between the rotor and the hub, and ... yeah I dunno.
 

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Save a horse, ride a....
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I've heard that overtightening the wheel nuts can warp rotors, but I think it's more likely in a case where some grease monkey (like at Canadian Tire) uses an impact wrench and torques them to near failure. If you tightened yours by hand, I don't see how they could have warped. Are you sure they're warped? Is it possible something else is causing the squeek? You used anti-seize etc etc on the surfaces that slide on each other? How did you turn the piston back in? Why don't you pull em off again and reinstall just to be sure.
 

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Twizzler
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Discussion Starter #5
Anti-seized everything necessary and no rust is present. I have the VW tool for rotating the piston back in no prob there its just the rotor is warped. When I spin it by hand it ever so slightly rubs against the pads and at that point is when it does the "taxi-cab" squeek. I always hear taxi's make this sound. I've had the brakes apart twice now and can;t find anything wrong, once the system was bled out piston retracted with the VW tool and no damage everything looks good, the second time no bleeding of the fluid so I just slid the caliper/pads back on. Would this cause any significant drag when driving, I mean to the point I'm wasting gas??? I'm lost and I'm tired of dismantling the rear brakes over and over.:( I have a couple of torque wrenches now, but I'm still interested in the myth of rotors warping from overtightening, I always hand tighten them and in the past with my other brake set I would rotate the tires all the time with no effect??
 

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Is it dragging and catching at one consistant point on the rotor?

The pads do lightly drag against the rotor at all times. This is perfectly normal. I have had to redo the anti-squel on the back of the pads when they started squeeling again.

It is also possible that you just got a bad rear rotor... it happens.
 

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180 Degrees out of faze
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The usual reason for rotors to warp is due to heat. Are you using OEM pads, or something else?
Over torquing the bolts by hand would require a lot of effort on your part.
 

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Only thing I can say is I KINDA had that some weird problem where it'd squeek in the same spot when rotating. I hit the rotors w/a hammer on that side of the hub and all of a sudden it moves. Last time, I tightened down the lugs w/o the wheel and made sure the set screw was tight, then removed the lug bolts and mounted the wheel. I doubt it made a difference though.
 

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Twizzler
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Discussion Starter #9
Thanks all for the responses I appreciate it:) And yes the whoop, whoop sound comes consistently from a spot on the rotor. I mean if I had somehow mounted it off angle, somehow it would either lean toward one pad or the other evenly not the whoop, whoop you know like a warped rotor. The problem just bugs me so much, the temps have dropped here now as well so taking it apart for further diagnoses is difficult. Another thing, if its warped should'nt I feel it in the brake pedal?? Or not, because the rear brake is so far from the master the difference in pressure would'nt register as a notable pulse??:confused: I'm going outside again to jack the car up and spin the wheels.
 

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Twizzler
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Discussion Starter #10
Yes!! these are OEM parts removed from a 2003 1.8 NB with only 200 miles on them, brakes were swapped out for Porsche brakes. And yes I retighten doing the star formation to even out pressure.
 

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Twizzler
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Discussion Starter #11
What about if... when retracting the piston on the one caliper with the AUDI/VW brake piston tool I didn't retract it all the way, I think on one of them I remember the piston not being pushed all the way in and on the other the piston was retracted all the way until the piston seal was nearly reversed looking. The one that wasn't all the way in was far enough that it wouldn't interfere with mounting the pads and onto the rotor. Does the piston operate from some fixed point after it is retracted?? So if it wasn't retracted all the way the set point would be closer to the rotor than one that was retracted all the way, hence my problem....maybe?? I checked it all out again and now can't really detect a warped rotor but instead one that has the pads rubbing really tight and on the other wheel the pads are barely contacting the rotor letting the wheel spin pretty freely??? Thanks again for the responses and info.
 

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180 Degrees out of faze
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NO, the piston does not retract back after you use the brakes. It will remain extended until you rotate it back into the caliper. So, it would not matter if one was out just a little bit when you put in new pads.
 

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whoop whoop

It seems i am having this same problem now, the brakes were all done this summer and have performed well, but now when cold there is a "whoop whoop whoop" sound for the first couple of dozen rotations of the wheel, after it rotates a few dozen times and warms up the sound goes away, however once the car has sat for a few hours its back.

Did anyone get any resolve with this issue? I havent had the wheel off yet to look if its indeed a warped rotor, but this sounds alot like my issue,

Cheers guys!
 

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It seems i am having this same problem now, the brakes were all done this summer and have performed well, but now when cold there is a "whoop whoop whoop" sound for the first couple of dozen rotations of the wheel, after it rotates a few dozen times and warms up the sound goes away, however once the car has sat for a few hours its back.

Did anyone get any resolve with this issue? I havent had the wheel off yet to look if its indeed a warped rotor, but this sounds alot like my issue,

Cheers guys!
There isn't one right answer for this problem. I can think of two reasons it could happen, mentioned already here, I'll repeat.

- Your pads could be loose. When installing the pad, some will have a glue back that you peel the cover off and stick to the caliper, others require you to paint the rear surface with a glue. It's called anti-squeal, which is a misnomer as it is really an adhesive used to hold the pads tight against the caliper so they don't fall in and touch the rotor. You can get brake anti-squeal from Canadian Tire or just about anywhere with auto parts. The Canadian Tire I went to, I made the mistake of asking the employee where to find it, ended up showing him where it was. Kids these days.

- parking brake might not be releasing properly. On my old brakes the rust/age of the components the brake and thus the caliper would not pull off entirely after releasing the e-brake. I replaced the entire caliper, pins, and bolts. 14 year old brake parts are kind of scary when you think about it. The rotors were replaced in 2006 and still had a ton of life so I didn't replace them.


OH, and don't start tearing apart your calipers unless you first check the condition of the pins and bolts holding them in place. If it looks really rusty and bad, you may find that after pulling them you've got issues putting them back together right. If you've never done anything with brakes before, might not be a good idea to take them apart at all as there is a special tool required to work on the caliper's piston, it doesn't just push straight in, has to be pushed while rotating. (mentioned already in this thread)
And do have a torque wrench for any tightening you do. The caliper pins need hardly any torque at all, far less than you will output with a standard socket wrench hand tightened by feel. You should have two torque wrenches, a small one from 1-30 nm, and a large one from 25-300 nm or around those ranges, every bolt on the car has a specific torque setting. I picked up both on sale at Canadian Tire for 50% off this summer.
 
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