Shelf life of anti freeze

[greencrew]

I have a gallon of anti freeze that is maybe 7 years old. What is the shelf life? Can I use it? If nothing else, I have a 47 JD model A tractor that I could use it in.

 

[UncleS2]

If it's regular ethylene glycol antifreeze, and it's sealed & undiluted with water, it should be fine. If it's been opened & tightly recapped, ditto. If it's been mixed with water all that time, best to get new antifreeze. My source? The prestonedotcom website. After reading this almost exactly a year ago, I used an old sealed jug of Prestone that was *at least* as old as your antifreeze. I't's still doing just fine.

 

[widman]

there is a high probability that the silicates have dropped out. At the very least shake it up.

 

[greencrew]

Thanks!

 

[oilyriser]

I bought some antifreeze last fall and put it
in my mom's car. A month later, I noticed a lot
of buildup on the underside of the rad cap. The
silicates were starting to drop out already.
I carefully looked at the jug, and noticed a
coupon on the outside. Expiry Dec 2001 !!!

The outdated antifreeze had been sold at
Canadian Tire, and was a new item in the store, so
I assumed it was fresh.

 

[Kestas]

Are you sure it wasn't the antifreeze doing its job? One of its functions is to deposit silicates (water glass) on the interior coolant surfaces.

 

[Ray H]

I don't pretend to know how long the shelf life of green ethylene glycol antifreeze/coolants, is, but I've developed a healthier respect for these despite their being laced with silicates and phosphates purportedly hard on water pump seals and bearings. A friend asked me to change her green Prestone coolant out the other day. I asked her how long it had been. She said, "Oh, I dunno - 3 or 4 years; maybe 5." It drained clear, clean and with no jelled glop in the bottom tank to retard flow. I flushed with water until it drained absolutely colorless in a clean drain pan. I just put Wally*World ST green anitifreeze/coolant concentrate in as replacement finally diluted to 50/50. '89 Toyota pickup with 171,000+ miles on the original water pump. I told her not to let it go more than 2 years/24,000 mile this time. We'll see whether my pearls of wisdom went in one ear and out the other...

 

[widman]

In general it's 12 to 18 months...... I have a nice little graph that shows the drop out rate of all the different additives used in different formulations. It's posted on my site for those who can navigate the spanish. If you want to email me I'll forward a copy.