Coolant change

[FarmallAddict]

I have a restored 1947 cub that was rebuilt about a year ago. The coolant in it is about a year old. Just for preventative measures I was thinking of draining and replacing the coolant with fresh stuff. There shouldn't be any crud in the system after just one year and I have seen no signs of overheating or blockages.

The owners manual says to mix water and washing soda and run the engine with the cap off until warm, then drain and fill with coolant. Do I even need to do that after just one year after a full rebuild? By most standards the coolant system looks to still be laboratory clean.

Thanks.

[Don McCombs]

You could test the specific gravity to make sure you’re protected. Otherwise, my opinion is that it would be a waste of time and money to replace it.

[JohnMihevic]

Since I rebuilt my 1948 Cub and installed a new radiator, I drain it every fall and refill with 50% Prestone and 50% water. There is no film, rust, etc. just "squeaky" clean. The main reason I do that is to put in anti freeze with fresh rust inhibitor, as that's what deteriorates with engine operation. Also, I don't flush with any kind of cleaners, etc. I am afraid there will be some left in "pockets" of the cooling system. I just drain and refill with fresh.

John M.

[Stanton]

...Do I even need to do that after just one year after a full rebuild?...

To answer your question, no, you won't need to flush your coolant system. Think I would test it, as Don suggested, before draining it. You may not need to replace the antifreeze but every other year.

[FarmallAddict]

If anything I might just drain the radiator and refill with new mix just to keep the corrosion inhibitors up to snuff, even if not really needed. I have a specific gravity tester lying around somewhere as well.

It could be a quick project to do on a rainy day.