I parked on a hill and applied my parking brake. I released the brake and noticed a strange noice coming from the left-rear tire once I was underway. I stopped and applied the parking brake and released it several times but it made no difference. By then I was within 1/2 block of my home so I came home. I removed the left-rear tire and the rotor was warm and the brake pad was applied to the rotor. The right rotor was cool. I interpret this to mean the parking brake hasn't released yet.

Is there a linkage that could have broke? Where might it be? When I apply the parking brake and release it with the lever, it comes back just fine...it just won't release the caliper. Does someone have a diagram for a 94' W140 parking brake? Is there a temporary fix to release the brakes so I can take it to a mechanic without ruining the rotors or pads? Please help. Thanks.

 

Parking brake (mechanical) and normal service brake (hydraulic) are different on MB....or at least in recent years.
The park brake is a drum type INSIDE the rotor. If this was sticking it is likely the rotor would be HOT and there would be a smell.
More likely your hydraulic service brake (caliper) is not retracting properly and allowing the pad to rub the rotor.
If so it is likely the caliper is part seized.
Possible it could be "serviced" with new seals etc. but usual solution is a new caliper.
Stuart