Coolant Flush

red29 · September 19, 2008

Anybody hear anything about how it's not advised to drain the radiator at the drain plug do to the plug breaking in the radiator?? Any feed back will be greatly appreciated.

Red29

C & A s Dad · September 19, 2008

The drain plug is plastic but I had no trouble with mine when I flushed the system.

Maybe someone else can offer more info.

NothinButBowTies · September 19, 2008

The drain plug is plastic but I had no trouble with mine when I flushed the system.

Maybe someone else can offer more info.

What did you do for your flush? I am assuming a drain and fill, but did you run a cleaner of some kind in between? I need to change mine out and looking for pointers.

Nick

C & A s Dad · September 19, 2008

I used a mild flush product from Valvoline (Zerex) but there are other good ones out there. I drain the system, fill with water and the flush and run it at least 20 mins. I then let it cool a little, drain and refill with water again. Run at least 20 minutes. I like to do this one more time to be sure all of the flush chemical is gone. I then refill with 50/50 water and Dexcool. Some people like to use distilled water but this procedure has been debated. Some feel it helps but some reports show that distilled water can lead to increased electorlysis.

If someone reading this is doing this procedure on a SUV with rear heat, be sure the rear heat is on high during the entire process. You want to be sure it is flushed as well.

Either way, at the end I add a bottle of LubeGard's Kool It. Part # 96001. This is an excellent product recommended in writing by Modine Raditor company. It is designed to increase heat transfer and lower coolant temps slightly. More important though is the fact that it will eliminate all chemical electrolysis which is a killer of any coolant system made up of multiple materials. i.e. Plastic, rubber, aluminum, iron etc.

MS3DALE · September 19, 2008

I had no trouble with my '99,However my '04 didn't even have a drain plug.

So somewhere between '99 and '04 they took'em out (along with the tranny pan and rear-end drain plugs)

CapitalTruck · September 19, 2008

Don't use any chem flushes. You have a drain plug? You lucky bastard! Just drain the radiator, refill with just water. Start car and let warm up and circulate, drain again, repeat until runs clear. Then drain the radiator one last time. Check the capacity of the system, add 1/2 the capacity in pure antifreeze, top the rest off with water (that gives you the 50/50 mix). That is how I did mine.

C & A s Dad · September 20, 2008

Don't use any chem flushes. You have a drain plug? You lucky bastard! Just drain the radiator, refill with just water. Start car and let warm up and circulate, drain again, repeat until runs clear. Then drain the radiator one last time. Check the capacity of the system, add 1/2 the capacity in pure antifreeze, top the rest off with water (that gives you the 50/50 mix). That is how I did mine.

Just curious, why do you say "don't use any chem flushes"?

I do not recommend the HD chemical flushes because some of them are acidic and if not used exactly as the intstructions indicate, they can cause problems down the road. However, the milder "10 min flushes" are harmless as long as the instructions are followed. I have used and sold them for 30+ years and never had an issue.

CapitalTruck · September 21, 2008

I have just found them to be unnecessary if the coolant is changed per recommendations. Two things are supposed to go into cooling systems: Coolant and Water. That's always been my take anyway.

Don't use any chem flushes. You have a drain plug? You lucky bastard! Just drain the radiator, refill with just water. Start car and let warm up and circulate, drain again, repeat until runs clear. Then drain the radiator one last time. Check the capacity of the system, add 1/2 the capacity in pure antifreeze, top the rest off with water (that gives you the 50/50 mix). That is how I did mine.

Just curious, why do you say "don't use any chem flushes"?

I do not recommend the HD chemical flushes because some of them are acidic and if not used exactly as the intstructions indicate, they can cause problems down the road. However, the milder "10 min flushes" are harmless as long as the instructions are followed. I have used and sold them for 30+ years and never had an issue.

JA_Silverado_04 · September 29, 2009

I had a plastic radiator drain stop-cock break on my Firebird. The smart thing to do is to buy a replacement ahead of time so you don't get stuck.

Unfortunately, on my '04 there is no drain. You are supposed to remove the lower radiator hose to drain it. I can see doing that multiple times is probably even more dangerous than doing the stop cock.

I also agree with the previous post. I would change the coolant while it is clean and is not even in need of a chemical flush. I think I read in the service manual it says never to use any chemical flush additives. It seems to me it can only be harmful.