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Dex cool, and I wouldn't waste money on the 50/50 stuff. It's almost the same price for only half the coolant. You can buy distilled water at the store for next to nothing.
I'm running LowTox (propylene glycol) coolant in mine. It's better for animals and the environment if it leaks on the ground, and it won't immediately destroy engine bearings if it leaks into the crankcase.
I used the Prestone Dexcool coolant and distilled water. Many of the modern coolants do not have the problems that use to happen with the mixing but it is a good idea to keep to one type of coolant. I chose Dexcool since that was designed for the many types of metals used in the engine.
Note that not including the overflow tank, you will only be able to drain off about 1.35 gallons of coolant at a time out of a capacity for the block+radiator (not including the overflow tank) of about 10.2 qts. For this situation where draining of the system is only from the radiator, I calculated/computed that to get a final dilution of 5% of whatever was in the cooling system to start with, you have to drain and refill with distilled water (not including the overflow tank) 4 times. So if you had 50/50 mixture to start with, after 4 drains and refills you will have 5% of 50% or about 2.5/97.5 mixture. Between each drain and refill, you should run the engine to ensure good mixing of the freshly added water with the left over mixture.
Then, if you think this is a sufficient dilution, you drain off what is in the radiator one more time and add pure coolant. For a 50/50 mix of water and coolant you will need 1.45 gallons but you will only be able to add back to the radiator about 1.35 gallons. The balance of 1.45 gal of the pure antifreeze should go into the overflow tank. Then once the truck is fully warmed up, top off the overflow tank with more distilled water.
There are block drain plugs but I could not even get one of them loose so I decided to do the flushing I described above.
I used the Prestone Dexcool coolant and distilled water. Many of the modern coolants do not have the problems that use to happen with the mixing but it is a good idea to keep to one type of coolant. I chose Dexcool since that was designed for the many types of metals used in the engine.
Note that not including the overflow tank, you will only be able to drain off about 1.35 gallons of coolant at a time out of a capacity for the block+radiator (not including the overflow tank) of about 10.2 qts. For this situation where draining of the system is only from the radiator, I calculated/computed that to get a final dilution of 5% of whatever was in the cooling system to start with, you have to drain and refill with distilled water (not including the overflow tank) 4 times. So if you had 50/50 mixture to start with, after 4 drains and refills you will have 5% of 50% or about 2.5/97.5 mixture. Between each drain and refill, you should run the engine to ensure good mixing of the freshly added water with the left over mixture.
Then, if you think this is a sufficient dilution, you drain off what is in the radiator one more time and add pure coolant. For a 50/50 mix of water and coolant you will need 1.45 gallons but you will only be able to add back to the radiator about 1.35 gallons. The balance of 1.45 gal of the pure antifreeze should go into the overflow tank. Then once the truck is fully warmed up, top off the overflow tank with more distilled water.
There are block drain plugs but I could not even get one of them loose so I decided to do the flushing I described above.
This is a fascinating approach. It had never occured to me to just add 100% coolant after the system has been flushed through with distilled water but in retrospect it seems like it should have been more obvious.
I'd previously been a fan of the ChrisFix method, perhaps because it aligned with what I'd already been doing previously. He basically has you run a few cycles of distilled water (plus multiple chemical flushes, which I'm a lot less of a fan of) then drain it out as best you can, then fill with 50/50 and hope for the best. I also live in a warm climate where antifreeze dilution is less critical, which probably let me get away with it.
I used the Prestone Dexcool coolant and distilled water. Many of the modern coolants do not have the problems that use to happen with the mixing but it is a good idea to keep to one type of coolant. I chose Dexcool since that was designed for the many types of metals used in the engine.
Note that not including the overflow tank, you will only be able to drain off about 1.35 gallons of coolant at a time out of a capacity for the block+radiator (not including the overflow tank) of about 10.2 qts. For this situation where draining of the system is only from the radiator, I calculated/computed that to get a final dilution of 5% of whatever was in the cooling system to start with, you have to drain and refill with distilled water (not including the overflow tank) 4 times. So if you had 50/50 mixture to start with, after 4 drains and refills you will have 5% of 50% or about 2.5/97.5 mixture. Between each drain and refill, you should run the engine to ensure good mixing of the freshly added water with the left over mixture.
Then, if you think this is a sufficient dilution, you drain off what is in the radiator one more time and add pure coolant. For a 50/50 mix of water and coolant you will need 1.45 gallons but you will only be able to add back to the radiator about 1.35 gallons. The balance of 1.45 gal of the pure antifreeze should go into the overflow tank. Then once the truck is fully warmed up, top off the overflow tank with more distilled water.
There are block drain plugs but I could not even get one of them loose so I decided to do the flushing I described above.
Thank you about your wealthy information christine_208
This is a fascinating approach. It had never occured to me to just add 100% coolant after the system has been flushed through with distilled water but in retrospect it seems like it should have been more obvious.
I'd previously been a fan of the ChrisFix method, perhaps because it aligned with what I'd already been doing previously. He basically has you run a few cycles of distilled water (plus multiple chemical flushes, which I'm a lot less of a fan of) then drain it out as best you can, then fill with 50/50 and hope for the best. I also live in a warm climate where antifreeze dilution is less critical, which probably let me get away with it.
But the next time I flush in the spring I'm going to be doing it your way.
Can you share your calculations? I'm not doubting you, would just like to see how that's done.
I'm a fan of Chris_Fix too. I've consulted his videos to educate myself on several topics. However I must admit my favorite is his video on the proper procedure for replacing the blinker fluid.
My father taught my brother and I how to do a flush on a 71 Ford station wagon. Where we lived (near Seattle) all of the water is quite soft as it comes from reservoirs filled with snow melt. This allowed for doing a regular flush with garden hose. But where I live now, we have well water that is a bit hard. So to use good water, you have to do repeated drains and refills. I think also on his old Ford (302) he was able to get much greater fraction out by using the radiator drain than we can on our Blazers.
As for my calculation, my hand-writing is horrible so I'm attached a pdf of a MS-Word document I made up to describe it. This was a good exercise so that I can a nice copy for myself in the future. I hope you find it useful.
Last edited by christine_208; 02-10-2019 at 01:21 AM.
Reason: fixed typos in attached file
02-06-2019, 08:45 AM
Which type of coolant
I hope you find it useful.