on a 78 volvo 242, i recently replaced a rear wheel bearing and seal, and the parking brake shoes, because it had been leaking and the shoes were fouled. after replacing them, the parking brake didn't hold much at all. my online books show an adjustment at each brake (which there isn't), and an adjustment at the brake handle, which i tightened as far as it can go. even still, the brakes barely hold, and in a test while driving will reduce your speed by 10mph in about 8 seconds. i want these suckers to be able to lock up, what am i missing here?

if it makes any difference, the replacements were beck-arnley.
also, the old shoes (oil fouled) held much better than the replacements, leaving me to wonder if the replacements aren't manufactured to the same specs as the originals or what

any advice on how to get this back up to spec? is another brand made to the right spec, or is there something else i'm missing?