Old-Style IAT Coolant: Prestone II, Etc. Available

Messages
32
Location
Louisiana
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.
 
Messages
36,461
Location
ME
Peak makes a traditional green. It has Phosphates which not all greens do; not sure how your mystery car can handle them. Supposedly it's hard on "some" water pumps.
 
Messages
1,429
Location
quebec canada
New coolant attacking silicon?change brand get a big rig pre mixed.newest is best .no silicate etc big rig use silicon hose all the time and haven heard anormal issue
 
Messages
3,332
Location
Bolivia
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.
 
Messages
2,053
Location
Sequim, WA
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. Ed
 

Buick8

Thread starter
Messages
32
Location
Louisiana
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.
 
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