We have an old 92 Sierra C1500
Trying to do some brake work. The right rear drum popped right off. The left will not. It will move a bit, but something is catching it. It’ll move a bit but then just will not budge. We’ve bought a puller and that won’t do it. Any ideas? Thanks
I assume you backed off the drum adjuster to retract the shoes, right?
PB Blaster, time and a hammer.
If that doesn’t work, a cutting disk, hammer and a chisel.
Maybe there’s a ridge worn into the drum that the brake shoes aren’t clearing. Try rotating the drum slightly at the same time you pull on it, might be able to wind the drum ridge over the shoes that way. Otherwise you’ll have to manually adjust the shoes to retract them further away from the ridge. Sometimes you have to look at the way things are configured on the other side to figure it out. There are usually access holes in the brake backing plate, you may be able to use those to get a piece of stiff wire in there to hold a shoe back or something.
If the drum doesn’t rotate at all , it is probably rust-stuck to the hub. I had that problem recently on my Ford truck. I was able to get some rust penetrant in the hub/drum area, then, after some soaking time, was able to break it free using a home-brew puller, patience, and some light taps with a hammer. Your local shop should have no trouble getting the drum off, as a backup plan. They’ll probably heat it with a oxy-acetylene torch.
Or the parking brake didn’t fully release on that side.
The last drum brake I worked on I was surprised to find that there was now adjuster window on the backing plate. Normally you would back the shoes off a little and pull the drum. This was on an 86 Buick. If you don’t have the adjuster window, about all you can do is turn, pull, etc trying to pull it off the shoes. Maybe have a ridge worn in the drum.
Now the backing plate did have the outline for the window but I have no idea if this was meant to be knocked out or not and the rubber plug installed. Maybe a pro here will know.
Assume nothing !
Thing is on some cars the adjusting window is not cut out. Just solid.
It can be knocked out with a punch and hammer.
Exactly, then take off the drum and remove the punched out piece before reassembly.
Also some have the adjuster slot in the drum ( all the Camrys I’ve owned) so those you have to remove the tire to have access.
Have you released the parking brake . . . ?
I am indeed assuming nothing 
Assuming it has been fully retracted as mentioned, what I have learned to do when all else fails is to remove the heads from the retaining pins at the backing plate. Grind or drill them off. Then just pull the entire works with the drum. It’s far less damaging than pounding and any other acts of frustration 
The pins are cheap to replace…
This tells me it’s not rust, it’s that the shoes aren’t retracted, either the adjuster isn’t backed off or the parking brake is stuck on. Maybe the cylinder piston(s) is stuck?
+1
On my father’s '66 Ford Galaxie 500, the adjusting window on one of the brakes did not line up with the adjusting screw assembly. I guess that the wrong backing plate was installed at the factory on that one wheel, so instead of using a standard brake adjusting spoon, I had to use a long & narrow screwdriver in order to reach that adjusting screw. This was extra time-consuming and not convenient.
Assuming you’ve backed off the shoes and released any attachments, a cheapo Harbor Freight “brake drum puller” has worked well for me to clear the rust lip on the drum.
Prior to buying the “drum puller” I tried hammering and using a variety of generic 3 point pullers without success but the drum puller, which attaches to the lug nuts, was the only thing that provided enough oomph to drag it out beyong the brake shoes
What if the adjuster was installed backwards? Wouldn’t auto-adjust, of course, but I’ve seen odder things.
Edit-could also be the wrong adjusting hole was punched out, the left and right backing plates are often identical, with two adjusting holes partially punched out, one of which is fully punched out. You can see them both here:
Do they still sell that product? If so, please post a link. I can’t envision how it attaches to the lug nuts.
I used an 8 inch Harbor Freight 3-jaw puller, but had to improvise the jaws b/c the original jaws wouldn’t grab securely to the drum. I did it more or less like the vdo below, but with the improvised puller and an ordinary hammer. One other change, I applied a little tension w/the puller, then applied the rust penetrant, and let it sit several hours to give the penetrant time to work first. If you did this sort of thing for a living you’d want to have one of these sturdy pullers designed for brake drums, per the vdo. With that tool, the drum is either coming off, bending, or cracking. hmmm … maybe there’s a reason diy’ers shouldn’t have that tool! … lol
That’s indeed possible if a prior brake repairer switched the adjusters right & left. They’re different side to side.
My truck’s adjuster is at the bottom, but my Corolla’s is at the top. The bottom orientation provides much easier access for the diy’er without a lift. Since the OP has already removed the drum on one side, should be obvious where the adjuster is located.
One good idea the folks at Toyota came up for the Corolla with was to drill and tap the drum face so you can thread a bolt through the drum to push it off the hub. (Note: The hole must be aligned correctly w/the hub. I use stiff wire to probe the hole to make sure the bolt will make contact.) This makes the drum removal job a lot easier on the Corolla. Unfortunately for the diy’er, even the factory service manual fails to mention this feature … lol …
The FSM for my Corolla says it should have that feature, but it doesn’t. A sizeable hole in the face of the drum big enough to access the adjuster mechanism from the front. That’s a good idea from the repair perspective , but it could possibly present some wheel balancing problems. My drums don’t have that hole, but with the drum removed its easy to access the adjuster from the front. Prior to drum installation I adjust the shoes from the front so the drum just barely fits, then I don’t have to make any further adjustments from the rear.
BTW, it is a good idea for the diy’er to take a photo of how everything is configured with the drum off for future reference.
Hopefully OP will come back and tell us of their progress. Removing a stuck brake drum is indeed a bit of a puzzle.
The problem with drum brakes is that is that they tend to build up a ridge/corrosions/schmutrz at the outer edge of the drum and when you attempt to remove the drum it’s stikking like glue.
Drums used to be turned/replaced every 12,000 miles but that’ s somethjing from the past.
Bottom line today, drum removal tool which further damage to the druns,
I’m going to throw this B. S. Card on that. Drums were turned/replaced when the brake shoes were replaced. Not every 12k.
Yeah, now that I actually think about it you’re correct. Geezer senility sneaking in 
In my defense, with an infrequently driven antique car where 12.000 miles is several years, wheel bearings pressed into the drums, brake cylinders tending to leak or sieze and rust being an issue, to avoid an unplanned failure I’ve unconsciously adopted more of a calendar approach to the brakes. i.e Every 3-5 years or 12,000 miles, while you’re in there just do it all.
But again you’re correct, in the past drums were replaced/turned when the brake shoes were replaced.
Back then it seemed like every gas station had a machine that could turn the drums, shoes were often relined and brake cylinders could be rebuilt … not today.
Ahaa the good ol days of maintenece.