RE: Replacing coolant...

[Z51JEFF]

Originally Posted by tomtom72

Jeff, what kind of corrosion? Flakes & scale...kind of white to ashen looking stuff? Most of the time that is the results of "galvanic Action" = two or more dis-similar metals in water. The condition makes a battery. The current causes the salts in the coolant to percipitate out of soloution, scale. You can look up "Electrolytic Corrosion" also, same thing. Make sure all the grounds on the motor are clean, tight & have liberal di-electric grease coatings....I might add that all the connectors in the harness could use the same grease.

Using steam distilled water in the cooling system will mitigate the galvanic action, no salts like tap water. Flushing using plain tap water repeatedly and then drain and then use distilled for a few flushes after the drained tap water comes clear should work for most normally contaminated ZR-1's. Then just fill with 1825-M spec coolant to 50/50 mix & make sure every two yrs at the most you repeat. The FSM says not to use any of the caustic flushes sold at the parts stores. If the flakes are really bad you can take out the T-stat and reassemble the housing so it leaks fairly well. Stick a hose in the upper fill tank and then idle the motor till the run-off comes clear. I doubt that your system is really scalled up as most people heed the warnings in our owner's manual about the two yr interval. The issue is that they use tap water every two yrs and you get the small amount of scale build up. Try just flushing and see what happens.


Tom

Thanks for the info Tom,the corrosion is white powder residue,very minor traces but want to eliminate any future problems.I dont want to completely drain the system and take a chance of getting air in the system so thats why Im draining off the fluid a little at a time and the topping of with the distilled water.Would the distilled water be better that tap water?Thanks again.