[murphyv310]

Hi Dawn.
K seal is a nightmare to get rid of. I had so much trouble with my last 75 due to this. There are good radiator flushing fluids available and in this case you most likely will need to do it two or three times. Some say leave for ten minutes but no at least a day. Try to get the engine hot with out over heating, do it at a fast idle 1200-1500 rpm, let it cool and keep repeating this as often as you can, once cooled down drain the coolant and flush with a hose for a good 20 minutes, I eventually got my garden hose into one of the heater hoses and flushed it through the matrix and through the block, water was coming out of the filler cap and all sorts of places.
The key is the flushing fluid will loosen the K seal and as much water as you can pump round the system should get it out.
A tip from Marinabrian is cartons of cheap fresh orange juice in the system, it's good at dissolving rubbish. Good luck