Today i pulled my rad to give it a good flushing out,
when i flushed water through it lots of pink "rocks/sediment" came out...
Im thinking the car has been filled full of block seal and sold but im not sure, or is it just rad stop leak?
Any ideas??

 

WaterWetter used to come in pink crystal form and it wasn't uncommon for it not to completely dissolve.

Maybe...

 

that sounds plausible, cause i ve always remembered block/rad seal as being powdered aluminum or copper.