how to clean out coolant lines

[globalgrooves]

getting my 64 230sl back into shape again, the metal coolant lines are restricted with hard water build up over the years, any ideas on how to clean them out, is there a solution i can let them soak in to loosen up the deposits?

[menesesjesse]

These lines are not that difficult to remove but my experience was that a lot of rust equates to the line being compromised.  I ended up having to buy the line from the resivor to the water pump inlets after a good cleaning.  The water is prone to sitting in the pipe during storage and rusting the inner part of that line.  Almost 300.00 with shipping from Germany for that part but you need it in good shape to ensure the doesnt overheat on the road.   
Jesse