Hello,

I have a 98 4wd Blazer. Can I use ATF in the power steering if I have a leak? Can I use coolants other than Dexcool?

 

No. Use power steering fluid.

Yes, but dont mix Dexcool with green by adding one to another.

 

As for coolants. I've tested the newer green and Dexcool types that have been reformulated to be mixable, at least so that they do not create a sludge, and I confirmed that they did not by mixing them myself. However, you might as well stick with just one or the other. I went with the newer Dexcool when I last did a flush of my cooling system.

 

The only reason to not mix the two is that for some reason it shortens the lifetime of the corrosion protection in the mix to less than in the lifetime of either pure coolant. The additive packages are definitely not complimentary. Dexcool will last longer than green, but only if you keep it pure and keep the system completely full. Introduce a lot of air (oxygen) and heat from neglected cooling system and you start making brown sludge out of the organic acid additive package. Original Dexcool formula had issues with degradation of some plastics - hence the intake gaskets on our Blazers needing replacement, and why the metal/rubber intake gaskets are so popular. However Dexcool has been reformulated since the beginning and supposedly no longer poses that problem. I use it in all my GM vehicles, including my S10 racer (because they all have aluminum radiators). Mine has been in my Blazer for 7 years without forming brown sludge. Time to change it this year. I hate to admit it but my 2006 Pontiac G6 (bought new) still has the original Dexcool in it - but it also still looks fine (it was always kept full and no recovery tank - entire system pressurized). No brown sludge or discoloration, but need to change it too. The Avalanche and the S10 have been changed within the last couple of years during unrelated repairs.