Ya gotta wait till the thermostat opens. I usually button it up and go for a drive. Watching the temp the whole time of course.

 

When you flushed the engine did you pull the lower rad hose and the two engine drain plugs. Note the one plug on the righthand side by the starter is a bear to get at; when I did mine I left it in, park it on a grade and drained the engine coolant.

 

I only pulled the lower radiator hose. I just pulled the driver side block drain & radiator hose and afterward was able to fill about 4 gallons in the reservoir. I can't believe there's still over 2 gallons still in there after pulling the radiator hose and block drain.

 

Get a battery hydrometer (any place that has automotive supplies, including Walmart or Amazon) so you can get a reading on the mix. Drain some coolant and refill with straight coolant to increase the percentage as needed. If you go a little too far, like to 60%, it won't hurt anything either. Yeah, be careful trying to just let out a little at a time, like a quart or 2.

 

Here's what I do. I know that after doing a very thorough job of flushing the cooling system including the heater, I add pure Dexcool for almost 1/2 of the system capacity, so 12 qts or so. I may not be able to get all 12 qts in, so if not just add 9, or whatever I can get in. Then run the engine and measure the concentration with an antifreeze tester. It may not test to 50%, so I would drain out enough coolant/water to put in enough straight coolant, about 3 gallons. I KEEP THE MIXED COOLANT in the empty jugs. Again measure concentration. Adjust by adding more Dexcool, draining a little from the cooling system into the jugs to make room for the concentrated Dexcool. Doesn't take long to get the concentration you like. Mixed coolant lasts a long time. Measure the concentration and put it on each bottle so that when you need more coolant, you know what you're using.

 

I would think that if you can fill to 12qts /25.4qts that is close enough. By the math that comes to %47. Initially you indicated that you were only able to get 9qts in by draining radiator and lower hose only. So pulling driver's side block plug you got 3 additional quarts? It would seem that pulling the easy plug on the drivers side filing with straight AF is the best method. As stated above if you really want to get 50/50 you could mix it up and drain some of the 47/53 and refill with straight coolant. I never really have trusted the floating balls testers to measure very accurately. I run a 15/85 in my dirt bikes as that gives better engine cooling and still provides just enough freeze protection. You do give a up a bit of bol protection but it is a tradeoff between rejecting the heat before a boil or preventing a boil by have a higher building point. In generally if you are running hot enough to boil its going to boil regardless of the ratio. Tyring to mix to %15 percent the floating balls testers are pretty much useless.

 

IIRC the block drain the front passenger side is also pretty easy to get to. Pull the inner fender and it's right there.

 

….. Was in the Automotive Radiator Business for over 40 years; some folks got it right by saying to also drain the block using the block petcocks & removing the lower hose. … Now would also be a good time to consider hoses, thermostats for sure, & pressure cap…. In my business & from personal experience I always aimed for 2/3 antifreeze & 1/3 GOOD water or distilled water… With 2/3 antifreeze you get superb corrosion protection!…

 

pure antifreeze with no water you would get no heat, I believe the water mixed with coolant gives you the heat you need in winter months. so I would go with 50-50 mix 0r 60-40 % of water.

 

Pure antifreeze has a lot lower freezing point and higher boiling point. Down side to pure glycol is reduced heat transfer. Yes you will get heat but you will not get as much heat, nor will the engine shed as much heat to the atmosphere through the radiator.