Mike, a collapsed brake hose at the left rear caliper may be restricting brake fluid flow and not allowing the caliper to release properly. Suggest opening the bleeder and see if you can get the caliper piston(s) to move without too much effort. If not, you need a new caliper. In older automobiles (approx. 15 years) it's a good idea to replace the brake hoses.

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Fred Hoelzle