cooling system cleaning

[phri]

Hi,

I am going to replace the radiator on my gtv3.0 as it developed a minor leak. I intend to do this myself and also want to give the rest of the cooling system a good clean and change from green to red coolant.
Should I use one of these radiator flush products? and if yes what's the best time to flush before or after the installation of the new radiator? Any other tips? (I am still new to the alfa v6)
btw I replaced the thermostat 6 months ago

[colcol]

If the coolant is really dirty, give it a flush with clean water 1st, if not drain the old coolant and replace it with clean water and some radiator flush, with your favourite brand of raditor flush, they all seem good, then run it for however long it says on the instructions, then drain the radiator flush and rinse all the dirty coolant out of the system, when you are driving around with the cleaner, make sure your heater is on, so you have the cleaner going through the heater core, when you are happy that the system is clean, replace the radiator, you don't want rust and sludge clogging your new radiator, thats why you put the cleaner through with your old radiator, then with the water drained out, put the right amount of coolant into the system, but be carefull of air locks, start by filling through the highest point, i use the coolant overflow tank, with the hoses off, and slowly fill the coolant tank, and as coolant starts to dribble out of the lower hoses connect them back up, and continue up until you do the highest hose, this will hopefully eliminate any air locks, Colin.

[colcol]

The reason you have the heater on when you are cleaning cooling system out is so that the cleaner runs through the heater, now i don't know if the 156 has a heater tap or a door to shut off the heat, perhaps someone could tell me, my 33 and Commodores i work on have heater taps, Colin.

[colcol]

Replace the coolant with pink or red coolant, the 4 year long life type that does General Motors GEN 3 V-8 's and Alloytec's, use Paraflu, Nulon, Penrite, Repco or whatever you prefer, just make sure the specs are as for Alfa Romeo GTV 3 litre V6, don't use the green coolants, as they are not suitable for the newer Alfa Romeo's, Colin.