Lots of reading before posting my question. I found that in my '03 RK, the pistons in the brake calipers end up sticking. It gets to the point that only one is actually pressing out, and results in a very soft lever, and even pulsing that mimics a warped rotor.
So I pulled the caliper on one side and squeezed the lever. Sure enough, only 1 piston out of four moved. I shot them all with a generous spray of brake cleaner, and now the second one on the same side moves freely. However, the two on the other side don't move at all. Before getting radical and disassembling the entire caliper, I thought I'd ask if anyone knows a trick to get the other side clean and moving freely. Right now it's sitting with a nice soak of cleaner, and I'll check it again in the morning. My only idea is to put a few washers under the brake pad to create a space between the pad and the piston, and then give it a squeeze. Any other tricks I can try?

 

http://www.lyndallbrakes.com/service-tech/

 

Bro, I have a 2012 Road King, less than 1,000 miles. The front brake pads were replaced first time just under 500 miles, due to uneven pad wear. It will require a 2nd replacement for the same reason soon here. I gather, this is a common problem with the "touring" models. Can't see myself breaking the bank for a well-known problem with HD Touring brake systems. My bud at the HD school-house suggested moving the moto on neutral and see if pads are dragging, and also check if there are spacers still in place. I'm new with HD motorcycles. Have yet to determine if I'm going to let NWHD work on the brakes, or do it myself... It didn't seem like a big deal to them, so must be common brake system defect. I'll post what I figure out with my RK brakes. thx!

 

Pull the caliper. Block the free ones and use the brake to push the other out. Remove the rest and clean up. See what you got. If piston is slick and groove in caliper is not pitted, rebuild it with new rubber and use the special caliper grease speced out by Harley in their overhaul kit. Replace with new pads. If caliper is pitted, get new caliper,pads and rotors.

 

Pretty much exactly what I did, thanks! Since my post only an hour ago, I stuck a screwdriver between the stuck side of the caliper and the pad. When I pulled the lever, the last two came free. I sprayed them with cleaner and now they will sit until morning. Totally easy once I knew what I was doing. I suspect the left side will take all of 20 minutes.
I've got new rotors and pads on now, so I'll report back after the next test ride.

 

I was just going to pull mine apart. My left side caliper is dragging so bad it will cover the wheel in brake dust after a 100 mile ride like I didn't clean it in a month. Thanks for the post with tips on how to fix it.

 

A 1/2 inch drive craftsman ratchet handle is the perfect thing to stick in the caliper without the pads to get all of the pistons out.
I clean mine about every 20k or so.