coolent change droplinks daihatsu sirion 2007 1000cc

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hi recently bought a sirion 2007 plate 1000cc.
14000 miles on the clock.
Anyway changed the air oil filter and oil change spark plugs.
Did it myself cost me 30 pounds including the oil. the oil filter came off with a lexus oil filter tool my mate had.If anyone wants one get them off ebay for a tenner.
So a couple of things the left front is knocking over rough roads so im changing the drop link doing both sides for what its worth.
1 is it common for a droplink to fail after 14000 miles Unknw
2 what coolent should i use to replace the old stuff with red or blue or green.