Do you mean the wheel cylinder blew its piston out, fluid leaked and you replaced the wheel cylinder? Those are dust boots. The hydraulic seal is inside. The pins push out on the shoes against return spring force to apply brakes. They can only extend out so far or will blow out as if you push brake with the drum removed you could wreck it.
There's no anti-rattle spring in there! Hold down springs for shoes, two return springs to anchor and one at bottom holds start adjuster from falling out. The rest is for parking brake which if not properly adjusted or frozen will mess up the whole show. These adjustments are in sequence or one will ruin the other's adjustments. Service brake is set first and should self adjust but with some time many don't.
Parking brake hardware operates the shoes without hydraulic pressure thru that bar connecting them with a spring on one end that does serve to stop it from flopping around.
If these parts are frozen, worn out of spec too rusted or broken you about need to toss all the stuff out on both sides, drums turned or replaced, inspect axle grease seal for leaks and plain do a full rear brake job.
Assorted "Erector set" hardware. Said already that these are asymmetrically opposite left to right or call it a "mirror" image much like a left and right hand glove. Star adjuster is reverse threaded for one side and shoe with larger area of friction material goes towards the rear.
The common problems to me are rusted on drums with a ridge making them hard to remove and backing off the star adjuster to make clearance, adjuster that fails to make up for lining wear, hold down springs stressed from forcing drum off can break and any of those metal pieces will ruin the brake crunching around in there.
OK - if that dust boot fell off or pushed off right away it is all messed up. Seems confusing to look at these but this was the way to make a simple brake that lasted well for about a century even before they were hydraulic.
If this confuses you tow it to a shop to properly do a rear brake job. It's brakes so too important to mess up,
T
