Thanks guys.Yeah my overflow box was pretty dirty oily and mucky so i kept overflowing it out .Just wondering people tell me to bleed it from the valve and some say dont what is the real reason and why?
you need to start the engine for a bit, top up the level when it drops, put the cap on when it dosnt take anymore water, let it build up a bit of pressure then crack the bleed nippl, slightly, you will hear the air escape, keep doing this until coolant comes out of the bleeder,
those genuine holden pellets are are broken up walnut shells, they are there to keep the water pump seals and other components clean and ensure a long life, this is what causes the brown sludge build up in the overflow resivour, think of it this way, if holden has it there in the first place, it meant to be there for a reason,
also alien, putting stop leak in is a little reckless unless you have a small leak that cant get fixed immeditly, barsleak adds sludge through the system to blocks small cracks/leaks, holden pellets break down and turn into tiny abrasive particles,
stop leak will not prevent electroloisis (<the word you were thinking of) the only reason for electrolis to occur is if there is a problem with the engine/body earth, if electrolis occurs, it from a poor earth, ie, the electricity then trys to earth through the coolant