One thing the article doesn=E2=80=99t tell you is that most coolants includ=
ing Prestone, Peak and other major brands use corrosion inhibitors that wil=
l normally protect for about 3 years and then they begin to be depleted to =
the point where they are not longer
protecting.the system. Some think that=
they can just buy a can of some sort of inhibitor at an auto parts store a=
nd add it to their system. However the antifreeze packaged by the manufact=
ure used a combination of inhibitors, anti-foam agents and water pump seal =
lubricant that were compatible with each other. Adding an unknown can of i=
nhibitor might cause it to interfere with one of the original components an=
d cause more harm than good. So, it is always a good idea to dump out your=
radiator and refill with fresh antifreeze and distilled water. This also =
gets rid of any solids in the system that are a result of the inhibitors re=
acting with the metals to protect them. The freeze point of the solution w=
ill not change but testing your radiator for the freeze point doesn=
=E2=80=99t tell you the condition of the antifreeze corrosion inhibitors an=
d other necessary additives. I worked for Dow Chemical back in the 60=
=E2=80=99s 70=E2=80=99s and early 80=E2=80=99s. At that time Dow was the s=
econd largest producer of ethylene glycol automotive antifreeze. Union Car=
bide (Prestone) was the largest and DuPont (Xerex) was the third. Since t=
hen Dow has purchased Union Carbide and recently merged with DuPont so they=
are the world=E2=80=99s largest producer of antifreeze. I used to mar=
ket Dow antifreeze to the major automotive companies, GM, Ford, etc. I als=
o sold private label to most of the oil companies such as Mobil, Standard O=
il, Sun Oil, Quaker and others. Dow sold it to them in their labeled cans.=
Back then Dow=E2=80=99s recommendation was to replace the antifreeze =
in ones vehicle at the end of the second year of use. I still do that tod=
ay and have never had a corrosion problem with any vehicle that I have owne=
d. I also replace the pressure cap every two years at the time I chang=
e the antifreeze because most of them loose their pressure holding ability =
after about two years. This is due to the weakening of the spring and the d=
egradation of the two seals in the cap Sure, the antifreeze may have l=
asted longer than two years so I might have spent some money that didn=
=E2=80=99t have to be spent. But I think that never having had to replace =
a radiator or water pump due to corrosion over the 39 years I have owned my=
GMC has more than offset any extra expense from changing the antifreeze=
sooner. Emery Stora 77 Kingsley Frederick, CO > On Jan=
3, 2018, at 5:39 PM, Ernest Dankert wrote: >=
> Disclaimer; Must be true I read it on the internet ref. A. Lincoln.=
> > I have successfully used an oxalic acid to clean solder corrosion=
at the tube ends. It was a 2 part; part A was a cleaner and part B a neutr=
alizer. > That 25 years ago; fixed the coolant flow and improved the run=
ning temperature. Definitely not recommended for aluminum components and no=
longer > available at Autozone or Advance Auto. At the time I could vis=
ually confirm the effectiveness of the treatment. > > Here is a nice =
explanation of corrosion inhibitors > >
http://www.lytron.com/Tools-an=
d-Technical-Reference/Application-Notes/Preventing-Corrosion-in-Cooling-Sys=
tems > > > There are references to using muriatic acid (hydrochlori=
c acid) to clean cooling system. I would NOT try this venue unless it is a=
"nothing left to > lose" and not under any circumstance with aluminum.=
> -- > 1977 Eleganza II > Ogden NY > > _______________________=
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