whitting63

How often should you flush or change coolant? I drive my 67 about 1000 miles per year

Redbird

With that kind of mileage, I would guess about every 5 years. We can all get parnoid and drain the motor, pull the engine, and place on an engine stand until we drive again. Use a recommended coolant with distilled water and you should be okay IMHO.

capevettes

I've had pretty good luck changing the coolant every 3 or so years. 50/50 mix of distilled water and anti freeze.

66since71

Antifreeze never wears out, but the corrosion additives and wetting agents do. You can buy just the additives. I never change the antifreeze in any of my cars, I just add the additives every three or four years. Prevent the corrosion, and you never have to flush its by products out!

The antifreeze in my 66 is 20 years old and still bright green and working fine.

Harry

Powershift

Harry:

Many folks do this, and it seems to work out okay. Especially prevalent with the big diesel rigs.

However, the glycol in the antifreeze will slowly degrade/decompose over time to corrosive organic acids. The additives MAY keep them in check indefinitely, but maybe not. I would suggest a complete drain and refill at some point.

Larry

Fawndeuce

If your car has an aluminum rad, especially an original Harrison, do not use a flushing agent.



Paul

tuxnharley

Same here, but I "only" go 10 years between changes! A ph test strip (remember your High School chemistry?) check every year or so is a good way to monitor the condition/possible deterioration of the anti freeze and decide when to use the additives. I like Griot's Garage "Corrosion Inhibitor" or Prestone "Super Radiator Anti Rust".

sub006

I have heard that distilled water is for certain uses, and auto engine cooling is not one of them. A chemist and car guy I respect claims distilled water, lacking minerals, tends to pull them from metals it contacts, thus you end up with what you tried to avoid.

OTOH, some luxury car brands have specified distilled with coolant for some years, yet AIR Rolls Royce USED to specify 100% coolant, which I think would lower the boiling point.

I kind of doubt Chevy puts distilled in new Corvettes, but don't know for sure.

Please enlighten me on any or all of the above!

Powershift

Distilled water is your friend. What do you think Prestone and Zerex use in their 50/50 coolant mix?? They do not use municipal tap water. I know for a fact that the Asian imports specify distilled water in their cooling systems.

Deionized and demineralized water are more severe types of purified water. They use special resins and reverse osmosis to reduce the mineral content to near zero. This is needed for certain industrial operations like making boiler feedwater for high pressure boilers and heat recovery steam generators (HRSGs) Most commercial distilled water (1 gallon bottles etc) is not in this category.

Don't know what else to say. Either you believe or you do not.

Larry