Follow John's instructions.  You will need to drain a precise amount of coolant and then top it off with straight antifreeze, not 50/50.

Since the engine and radiator are linked together with hoses, which contains more coolant is inconsequential.  Draining via the radiator will drain some of the engine and draining the engine will drain some of the radiator.


Lawrenceville, GA

Is most of the coolant in the radiator+hoses or in the block? Or is it about the same? Because I'll just drain where-ever the most is and then top it off with 50/50, then recirculate and mix it.

When you run the engine to mix the anti freeze, don't forget to turn the heater control on to also mix the heater core coolant.

John - "The Hoosier Hurricane"

For this issue, it doesn't matter where you drain it from.  Use the drain valve that is easiest to reach.

You can mix non 50/50 and 50/50.  The non 50/50 is antifreeze that has not yet been diluted with water.  50/50 is antifreeze that has been diluted and is 50% antifreeze and 50% water.

You save a lot of money by getting non 50/50 and mixing it with distilled water yourself as the 50/50 is not usually a whole lot cheaper and you're only getting half the amount of antifreeze.


Lawrenceville, GA

Can I just drain the radiator and fill that with non-50/50 antifreeze, then run the engine to mix the stuff? Can non-50/50 and 50/50 be mixed?

Check your chart on the anti-freeze jug and determine how much you need to add.  Then drain that much from any drain cock available, add the required amount of anti freeze (be sure you get full strength anti freeze, not the 50/50 mix that is also in the stores), and run the engine until the thermostat opens, and it will all mix.

John - "The Hoosier Hurricane"

I gotta pull an emergency drain of the antifreeze tomorrow in the cold because for some baffling reason her antifreeze is only registering two balls or -5/-5 range of protection. Pisses me off because I put new antifreeze in THIS year or last year. I've got a space-heater stuffed under her hood tonight just in case.

With the lower radiator hose off, couldn't you pressurize through one of the heater hose connections and blow most of the antifreeze out?

I have run across a neat drain valve that fits the YBlock and is a marine item.  Fits the radiator too.  All you need is a 9/16 wrench to open it.
Available through a marine supply store or on ebay.  All brass.  You can even put a 5/8 hose over the end to direct the flow.

                              




54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

It is.
There is no passage linking the two sides so if you drain one, then it only drains that side.


Lawrenceville, GA