Hi, is there any brand of the old-style antifreeze like Prestone II, still available? I have an older car (1970s) which has wet cylinderliners and an aluminum block; and the new OAT tech coolants are alleged to attack silicone, like my car's liner O-rings.
I use HOAT in everything. It has so many approvals, and I've never heard of attacking silicon.
I'm not sure what materials the CAT o-rings are made of, but I have a customer who has been using HOAT in his 80+ CAT engines from 3408 to 3512 series for about 7 or 8 years now.
As stated earlier, Peak(Old World Industries) makes a low silicate "conventional green" coolant. The major auto chains, Auto Zone, O'reilley, NAPA, ect. sell it bottled under their name also.
HOAT coolants that do not contain 2-EHA will be fine also.
It's the 2-EHA in Dexcool and the universal dexclones that causes the problem. It is a plasticizer and will soften PVC, nylon, and silicone rubber.
Hi, I did find Peak conventional, and it was easier to find than I expected.
Car is a Rolls-Royce Silver Shadow: they have aluminum blocks and heads, with wet liners. Some have claimed the OAT/HOAT chemicals attack the O-rings. Hard to know, when a car is 40 years old, if it was just at the end or if the coolant did it. I don't know what the O-rings were made of in 1970.
Anyway I did have the Mercedes-Benz coolant in it, which is Zerex G-05 I understand, and no problems after about 3 years, but it's drained now and to refill, I played it safe.