So the left front brake of my w123 has a bad tendency of dragging and getting quite hot, and eventually the wheel smells like burning brakes. Today I actually lost braking power due to overheated brakes. It seems after I apply the brakes firmly, the brake caliper does not release as it is supposed to. I tried replacing the caliper but this has not fixed the problem. What else could be the problem? I suppose my next step is master cylinder but are there any other more probable possibilities or any way to test to find out exactly what is causing this?

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1982 240D 225K


1986 VW Jetta (gasoline) 379K


1988 BMW 735i 168K