Definitely, a No on using Phosphoric acid through the whole system or any strong acid, the seals especially, would object. As mentioned, removing the radiator or isolating the heater core separately, becomes a different story as i will explain just what i did with my heater in a moment. The theory of using ospho, aka phosphoric acid(i believe the concentration is about 30%) with water being the primary, to convert inside the system is a good thought, but not applicable for the whole system. Using in it a radiator removed, i havent evaluated enough to be confident with suggesting.
I might be buying our old 89 ford 1/2 ton fire truck with the trusty 4.9l and 5spd which has sat most of the time for decades and may be doing more experiments with flushing. When i think about being a redneck, i simply see it as applied engineering, which anyone can do. Even degreed engineers do dumb stuff that would bewilder a seasoned redneck, bc they often lack the common sense.
For example I offer, how long would it take a engineer to figure out which gas can his diesel is in vs his gasoline? We are so @nal we would short circuit. My redneck self, would simply smell it, with the "official" test being to just dip your finger in it, with gloves or not, and rub the together. The gasoline is considered a solvent, and like alcohol would evaporate quickly, its why it does not store well and its chemical deterioration over time, diesel is oil based and wont evaporate and has a natural lubricocity to it as you slip it between your fingers. So, people can stop judging rednecks for not having feelings, i feel my fuel plenty, so get that **** out of here, as im late for fishing.
Thought yall would appreciate that. FTR, i short -circuited when i confused my jugs, of fuel not on the wife, when it first happened, until I thought about it a bit over fishing, aka redneck meditation.
(I did not have a circulation pump, else would have used that for my heater core.)
The 89 Ford service manual specifically states to back flush separately when flushing the system.
With that said, the reason i used white vinegar through the system is because its a weak acid, and my 100 year old friends talked about it being the best way of removing rust from the bottom of the inside of my antique tea kettle. Just let it sit for a day or two. Apparently, some tea aficionados prefer a little rust flavor in their tea, go figure, i dont.
For my heater core, i back flushed while letting clr sit. I used an empty milk jug to catch it, used a funnel i squeezed into the 5/8 heater outer tube, held it up and poured. If you keep the inner heater hose up some it will aid in it sitting in there. Using this method, i actually switch directions, let it sit for 10 minutes and then with my compressor set to 40psi and not making too tight a seal blew it out. Using two milk jugs allows you to pour what came out back in while keeping most of the particulates in the jug. I put the jug low between the radiator and engine as i removed the alternator and vaccum pump.
I then flushed 6 times going both directions 3 times, alternating using a super-saturated mixture of baking soda, sodium bicarbonate, a base to thoroughly neutralize any acid in the clr left over. You will notice the chemical reaction as you pour it through and the bubbles coming out. I let it sit in there the first few times. (On hindsight, when flushing the entire system again, i would start with the vinegar, before using the base, where this time i did the base first through the whole system and warmed it up, also after draining the coolant originally, i would have used a heater core bypass kick before the base then vinegar flushes so that i wouldnt be bringing all the heater core crap into the system and it circulating back through the thermostat.)
I would not care about the coolant system this much if it wasnt for the criticalness to the operation of my motor. I knew none of this before this truck as its my first diesel.
Its no different than drinking sugary soft drinks, with phosphoric acid ironically, why going to the gym everyday. If that is all you drank, regardless of being in your early 20's and fit as a fiddle, you would suffer from kidney, renal, failure within a few months.
Now to finish painting my engine parts i removed, so my engine can compliment my redneck sophistication. Im using ospho on the rust and doing more redneck applied experiments.
PS never feel bad for reigniting old threads, because someone reading it after the fact doesnt know the difference. Sometimes it takes a few years of meditation, fishing, to discover some of the deeper existential redneck questions. I wouldnt necessarily ask someone directly in the thread from years ago, but you never know.
I may write all this up to put in the IDI Tech, as ive discussed it across several threads.