Liebherr fridge and black goo!!

Hi Folks,
I aquired a Liebherr used fridge, which seems to work OK but it is leaking black goo from a joint above the motor.
Looks like black gaffer tape around some copper pipe but its actually a black goo rather like bitumen.
Not sure why its there but it very soft and has dribbled onto the motor and the plastic fridge casing.
Do you know what it might be and what is its purpose.
The top of the motor compressor gets quite hot as well (around 50 deg C)
I have a picture but I'm not allowed to post links.
Any help appreciated
Cheers, David

It all sounds normal, the "black goo" is sound deadening for the capillary tube, it often drips down, but won't affect function

Thanks Happy, thats really helpfull.
The goo is around the point where a capillary tube meets the main tube.
I wonder why they can use something that doesnt soften up and dribble.
Thanks again, David

The mastic has been up graded on newer versions, which is more heat tolerant, the problem was found to more prevalant when the cabinet was enclosed in high ambient tempretures.