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07-04-2016, 08:43 PM | #1 |
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Rotor Groove and Pulsing/Vibration
I had the front right wheel off the car the other day (to replace a turn signal bulb) and realized the rotor had a noticeable groove in it about an inch from the outer circumference.
I've been getting intermittent pulsing/vibration under moderate braking. I checked rotor thickness and the pads on all corners and everything was within spec. Not sure if the groove could be causing the pulsing/vibration or if there could be another culprit.
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07-06-2016, 06:18 AM | #3 |
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^whs
Most rotors develop grooves as they wear and shouldn't cause vibrations
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07-07-2016, 06:51 AM | #4 |
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Here's a shot of the groove.
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07-07-2016, 02:11 PM | #6 |
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Ok, thanks. I'll have to check the pads.
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07-07-2016, 02:24 PM | #7 |
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How many miles on the car?
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07-07-2016, 10:21 PM | #9 |
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81K miles on the car.
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07-08-2016, 06:50 AM | #10 |
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Original rotors?
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07-08-2016, 11:20 AM | #11 |
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Possibly. High mileage/worn FCAB can sometimes have similar symptoms. Inconsistent brake shudder at speed. Because on first sight the rotor appears to be in decent condition.
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07-08-2016, 12:40 PM | #12 |
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Yeah, original rotors as far as I know. Bought the car with 64K on it and I haven't changed them.
Thickness checked out fine on the digital calipers though. Any other symptoms of control arm bushing wear? Everything still feels pretty tight.
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07-08-2016, 01:41 PM | #13 | |
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Quote:
If you can jack the front end up in the air, you can try and hit the control arm by the bushing with a heavy mallet and see if the bushing deflects. Bushings that are worn but have not leaked yet, will allow for some level of deflection when you hit the control arm hard with a mallet. Lastly...At 81K mile, they're about due for replacement ANYWAY. The shudder you feel in the brakes are from the control arm moving inside the bushing, transferring the movement into the steering knuckle into the steering rack and wheel. If you have a new set of rotors, new set of pads, and they're vibrating while braking at certain speeds, then I would suspect the FCABs require a replacement. Since you don't really know the age and usage on the rotor, then at this point it's a crapshoot. I'd replace the FCABs due to age regardless of whether or not that solves your brake issues. IMO.
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08-27-2016, 04:19 PM | #14 |
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Made an observation after washing the car today. I took the car for a drive to the end of the street and back to get the rust off the rotors and noticed the driver's side rotor wasn't cleaned while all the others were. It looks like the pad was only coming in contact with the inner diameter of the rotor. It's felt like the grinding/groaning/pulsing was coming from the driver's side (coincidence?). Chances it could just be the pads, or do I need to suck it up and buy new rotors too (even though they're in spec)?
Surface rust still on driver's side rotor Passenger ride rotor for comparison
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08-27-2016, 07:17 PM | #15 | |
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If that caliper is frozen in place or not moving freely that will give you a vibration under braking, and potentially also while underway since the caliper can't freely move away from the rotor surface.
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08-29-2016, 08:54 AM | #16 | |
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Quote:
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