Try re-installing your front axle, the following is courtesy of mcromo44, this includes info for making sure your fork tubes are in alignment as well.:
I did a rewrite and added some more in.
Here it is and perhaps it is Dropbox Worthy:
Keep in mind how critical it is to properly align the forks and front axle, noting I'm not aware of a factory manual that tells you how to properly align the forks on the front axle. Proper mounting of forks is as crucial as any work inside them or setup adjustments made.
Do a trial fit with both forks in place, bare axle fitted and lightly clamped on the side with the bearing preload end bolt, and very carefully nip up the lower clamps with upper sitting in place.
Then nip up the upper triple.
Then torque the lower triple.
Then torque the upper triple.
Then remove the axle.
Then release the triples on no bearing preload end bolt side, just enough so it can be be slid in the clamps with a hand tug, let it slide down, then back up to see if it nicely indexes in the upper hole.
Usually it does and that is what you are looking for. (If it doesn't, you have a misalignment problem.)
Then put the axle in, and move the released fork up and down to a position where the axle easily indexes into and smoothly slides through the other side.
With good forks, you should end with both sides fairly even in terms of projection distance about the top triple.
The carefully go about buttoning up the lower and upper clamps.
When it's all back together, loosen the axle clamp on the side without the bearing preload end bolt, and with the bike on the wheels and front brake on, Jounce as much as you can, thus letting the free fork leg find where it wants to be on the front axle, then torque it up the axle clamping bolts.
(the axle needs light oil on it for this to work properly - there is too much friction with a dry install for this to work).
Your forks are square and equalized to each other.
The axle will be easier to install with the weight of the wheel on it.
The axle bores won't get scored over time from repeated R & Rs.
Your fork legs should be reasonably centred on the fork tubes - noting how much slop they have in them.
Your fork bushings should be more evenly loaded with greater bushing area actually being utilized.
Your forks should end with less Stiction and less Friction.
Others may have a different approach for the initial squaring of the legs in the tubes.
Ideally, and hoping you won't be removing forks very often, the best way is to remove the springs, and do all the initial set up work with the forks fully compressed.
Some might suggest doing the fitting work mid stroke. Doing the work with the forks fully extended is not the best, but it's much better than just slapping it together.
Of course, all of this is wasted unless the steering head bearings are in excellent condition and have been properly setup, the triples are true, the forks are true, and the axle is true.
One last thing.
The bearing preload end bolt (that threads into the end of the axle) should not be torqued with that side's fork axle clamp pinch bolts also torqued. Loose or barely loaded pinch bolts is all you want. Use the axle clamp pinch bolts on the other fork leg to hold the axle whole you torque the nut. Otherwise, the axle is not free to load up on it's shoulder, and your bolt torquing will not be the indication of bearing load that it is intended to be.
Find a long straight road that has no one on it... do 8 or so HARD (im talking almost stoppie hard) 60 to 5 mph stops... never fully stopping, then after your HARD stops go cruise for a couple of miles to cool everything down properly. 10 bucks says your brake howl is gone.
From the manual when installing front wheel. Hold the axle and tighten to 43 ft lbs. Next tighten the right axle pinch bolts to 22 ft lbs. Install calipers tighten to 22 ft lbs. Now with the front brake applied pump the forks up and down several times to seat the axle and check brake operation by applying the brake lever. Then tighten the left pinch bolts to 16 ft lbs. Last check the clearance between the brake disc rotor and the caliper bracket on both sides. It should be .7mm or .03in using a feeler gauge. This is assuming that your forks are even at the top of the triple. This should get you fixed up unless you have a bad wheel bearing.
I have never experienced this (on a bike) so this is a wild guess. If I bolt up a front wheel and happen to get the fork tubes in a bind, I get a constant drag on one rotor but never a moan as you describe.
Once you're confident your tubes are properly aligned, if the problem persists try changing the pads. Or you could try filing a bevel into the leading edge of the existing pads - if they're new enough. Just a thought.