I'm planning on changing the antifreeze tomorrow, but I'm not sure how much of the mix i need. when i purchased my dually i didn't get a owners manual so I'm not sure how much antifreeze( and water) i need to add after i do a flush on the system. so does anyone know how much antifreeze do i need to add to my '95 f-350 7.3, I've googled it and didn't come up with anything conclusive, i looked on the ford website and their online manuals only go back to '96. thanks ya'll.
I'd get, at a minimum, 3 gallons of concentrate. When I flushed mine a few weeks ago, I bought 4 just to be on the safe side. I also got 20 gallons of distilled water for flushing/refilling but only ended up using about 15 gallons. Don't forget the FW-16/DCA-4 additive. If I remember right, 4 pints should get you the level you need.
Coolant capacity of the system is 32 quarts. So you would need 16 quarts of antifreeze and 3.5 to 4 pints of Motorcraft FW-16 (or is it 15?). You also can get the additive from IH, called DCA-4 in pint bottles or as I recall, DCA-64 in half gallon bottles. You can get coolant test strips from IH to check the additive level.
When you do a drain down of the coolant system using the radiator petcock, there is a considerable amount of old coolant retained in the block unless you remove the drain plugs on each side of the block. Doing it this way drains out all of the old coolant. Refilling will take 32 quarts of 50/50 coolant and additive.
I do a complete flush of the block/heater with fresh water using a Prestone radiator flushing kit. Drain down the radiator of water, add the DCA-4, add straight anti-freeze to the radiator (about 3.5 gallons) and the rest of the antifreeze into the degas bottle. This will mix over time and also result in a 50/50 coolant mix with additive.
You also can drain down the radiator, refill with water and run the engine. Repeating this process about 4 times results in a pretty fair flush of all the old coolant. Drain down the radiator and refill with coolant/additive the same way as doing the engine flush.