Originally Posted by JimSmith

First, it is not unusual for a service shop that is not very familiar with MBs to have difficulty refilling the brake reservoir correctly. Old cars can have discolored plastic reservoirs that make seeing the rear section is full very difficult, as when it is empty there is no fill "line" to detect and an inexperienced mechanic may conclude the rear section is full when it is empty. Part of the problem can come if the shop is full and they do this in the lot where the car might not be on level ground. Nose down at any significant angle and filling the rear section (normally done by overfilling the front section) and this becomes near impossible.

As to your state of repair, I recommend you purchase only new or rebuilt by a professional service brake calipers, new hoses and start over. While you are at it, jack up the rear of the car, and try rotating the wheels by hand. IF the service brake is dragging, open the bleed screw and see if that changes anything. If you are lighting fires due to braking friction you should have very apparent drag. If opening the bleed screw does nothing, take the caliper on the side or sides that drag off and see if the problem goes away. I have had a buddy drive with the emergency brake on because the warning light went out on the dash, and cause the wheel bearings to fry (no fires though), then seize at highway speeds and spin in the bearing housing. Big bummer.

But you need to identify what is dragging. The service brake, the parking brake, or the wheel bearings. Or is the problem something else? Like fuel dripping on the brakes? The driver's side has a breather line, the main fuel line and the return line tucked up in the wheel well, and they generally rot out by now.

Good luck,

Jim

Originally Posted by kerry

Where are you releasing pressure on the line? At the caliper or at the master cylinder?