There are a lot of ways to change coolant but systems are a little harder to flush with no radiator cap and a reluctance of some folks to disconnect hoses to do a full flush.
One way is through dilution which I recently used. This was a 2005 Ford Taurus OHV with 12 quart ( 3 gallon system.)
Mine still has a drain valve on the rad, so I did not have to disconnect a hose. However I did remove the plastic wind deflector from underneath the radiator, a job made easy with my Dewalt impact driver, in order to access the valve.
I drained the rad and got back two gallons, including the pressure tank which by itself holds a half gallon. On this car the P tank is active and takes a side stream of coolant from the engine. The fluid is hot to the touch after a drive.
So, with two gallons back that meant there was still a gallon in the engine. I added two gallons of distilled water through the coolant tank and took it for drive to run errands, with the heat on. I got home, let it cool and drained the fluid. I then added two gallons of distilled water again and did the same procedure. I drained it, confirmed it was mostly water with very little of the original coolant, then poured in 1 gallon of 100% concentrated coolant and and 1 gallon of 50-50 distilled water and coolant. This would have brought me close to fifty fifty coolant and water. I have attached three photos of the coolant freezing point with my density based coolant tester. The first photo indicates the freezing temp is off the scale and working with a density chart that would indicate about a 65 to 70 % coolant concentration. This common up here in Canada. After diluting with two gallons of distilled water, it showed a freezing point of -10 F which indicates a concentration of about 25%. Finally, after diluting it a 2nd time the freezing point was off the scale in the opposite direction indicating mostly water. By the way, the math seemed to work but I don't want to bore anyone. Enjoy the photos. This posting was brought to you by Prestone with Cor-Guard.
One way is through dilution which I recently used. This was a 2005 Ford Taurus OHV with 12 quart ( 3 gallon system.)
Mine still has a drain valve on the rad, so I did not have to disconnect a hose. However I did remove the plastic wind deflector from underneath the radiator, a job made easy with my Dewalt impact driver, in order to access the valve.
I drained the rad and got back two gallons, including the pressure tank which by itself holds a half gallon. On this car the P tank is active and takes a side stream of coolant from the engine. The fluid is hot to the touch after a drive.
So, with two gallons back that meant there was still a gallon in the engine. I added two gallons of distilled water through the coolant tank and took it for drive to run errands, with the heat on. I got home, let it cool and drained the fluid. I then added two gallons of distilled water again and did the same procedure. I drained it, confirmed it was mostly water with very little of the original coolant, then poured in 1 gallon of 100% concentrated coolant and and 1 gallon of 50-50 distilled water and coolant. This would have brought me close to fifty fifty coolant and water. I have attached three photos of the coolant freezing point with my density based coolant tester. The first photo indicates the freezing temp is off the scale and working with a density chart that would indicate about a 65 to 70 % coolant concentration. This common up here in Canada. After diluting with two gallons of distilled water, it showed a freezing point of -10 F which indicates a concentration of about 25%. Finally, after diluting it a 2nd time the freezing point was off the scale in the opposite direction indicating mostly water. By the way, the math seemed to work but I don't want to bore anyone. Enjoy the photos. This posting was brought to you by Prestone with Cor-Guard.
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