Do yo need to bleed the rad system after changing and refilling
 

Do yo need to bleed the rad system Im swaping all my water pipes with new ones http://images.ibsrv.net/ibsrv/res/sr...lies/smile.gif just wanted to check will i need to bleed the system after and if so how ?
plus how much coolent is best to use cheers guys

yes you will to bleed the system.
newage imprezas take 7.7 litres of coolant, classics slightly less i believe.
to bleed, fill the system completely with the header tank cap off. give all the big coolant pipes a good squeeze to force air bubbles out. fill the expansion tank also.
Some people say filling from the coolant pipe that goes into the turbo (you will need a funnel for this) is a good one to fill from to avoid air locks.
once full, turn your heater to full hot and start the car, let it get up to temperature and leave the header tank cap off, keep periodically squeezing the pipes to force out air bubbles. once up to temp refit the expansion tank cap. take it for a drive and leave heater on hot, keep an eye on the temp needle to make sure it doesnt do anything weird like over heat. check that the bottom hose is getting hot to indicate that the thermostat has opened.
Leave to cool down and re check coolant level.