How often to change antifreeze

[John S.]

Re: How often to change antifreeze

Duke,

Thank you for the information. I will be doing as you instructed before I do any more distance driving.

John

[Larry M.]

Re: How often to change antifreeze

I recommend using DISTILLED WATER for mixing with the antifreeze.

If you do not drain the block through the two block drain plugs, but instead use the drain the radiator, refill, run the car procedure to flush the system, then I would make the last one or two water refills using distilled water. This will ensure that what remains in the system is essentially distilled/mineral free water. Then just add the G-05 antifreeze.

The cost of distilled water is small compared to the benefits in using it with the antifreeze. I have learned this through experience over the last 30 years. It does make a difference.

Larry

[James G.]

Re: How often to change antifreeze

Even in the old days, we ALWAYS said every 2 years or 25000 miles, which ever came first.

Dukes flush method is dead nuts right on.

We use to remove the thermostat. Drain the radiator. Refill the radiator with just water and leave the petcock open so the radiator continues to drain. Start the engine, and add water until the over flow is almost full. Now readjust the spigot so the water going into the system equals the water draining out the radiator. Run until 100% clean water. Turn off engine, and completely drain system. We even used a pressure tester to help evucate the entire 18 quarts of fluid.

Now add you favorite new mixture. In the old days, always 50% coolant and 50% water, and with an 18 quart capacity, that is 9 quarts of 100% coolant or 2 gallons, plus one qt. Often people add one gallon and think all is well. Wait for that 2 degree night, Opps ! Many people wanted distilled water.

Block plug removal is a good idea if the fluid is rusty looking when removed.

Old green coolant lost its rust inhibetors after 2 years with NO DRIVING miles.

BE CAREFUL of the heater core. I have seen more than one START to leak after a good clean out of the system. The crud was keeping the hols plugged.

[Brian G.]

Re: How often to change antifreeze

Is the coolant in the overflow reservoir figured into the 18 qt. capacity?

[Lorne G.]

Re: How often to change antifreeze

Brian, My big block does not has reservoir but I believe the 18 quarts is in the block and radiator only.
Lorne

[Brian G.]

Re: How often to change antifreeze

Thanks Lorne.