![]() But we considered that to be beyond the scope of our testing. ![]() Certainly it could be achieved by dismantling the engine. ![]() When we followed Evans directions for conversion, and did it ourselves, we were able to successfully achieve the required 97%+ coolant removal in about 60% of our test vehicles. We found typical conversion costs $150-$180 in labor, plus a minimum of one gallon of conversion fluid at a cost of $34 per gallon. Evans also has a list of authorized conversion centers, where vehicles can be taken, and mechanics perform the conversion process for you. But larger systems will require two gallons. To aid in this process, Evans sells a conversion fluid that can be used to facilitate more effective removal of previous coolant. This would not be acceptable for conversion to the Evans products. In our testing, when we followed the Evans procedure for complete removal of coolant for our various test vehicles, the average observed removal rate was 94%. Engine block frost plugs must be removed, the radiator must be disconnected, hoses evacuated, etc. But doing so is mandatory in order to meet the Evans conversion requirement. It can prove problematic to fully remove 97%+ of coolant from a system. The result is reduction in coolant pH, and corresponding corrosion problems. When this happens, water combines with the glycol in the Evans coolant to form glycolic acid. If only 3% or more of coolant previously used in the system remains, the corrosion resistance of Evans coolant is lost. It is important to note that this level of corrosion protection can only be achieved if the coolant consists of 97%-100% Evans coolant. This can cause granular fatigue in aluminum radiators, and result in stress cracks and failures, depending on the thickness of the metal. Inhibitor deposition causes hot-spots to develop on metal heat exchange surfaces. In a cooling system, this can cause problems. Inspection of the aluminum test coupon indicated inhibitor deposition from the Evans product. The only concerns were: (a) the relatively high rate of corrosion for solder, and (b) the net gain in weight on aluminum. The product provides very good overall rates of corrosion protection, and passed ASTM D1384. * A negative weight loss indicates a weight gain. We ran Evans waterless coolant through ASTM D1384 tests, and compared the weight losses due to corrosion (in milligrams) to that of No-Rosion for each of the metals tested: ![]() In our research, we evaluated each of these claims. Some of their advertised claims are: little to no pressure change during heat/cool cycles, less corrosivity, extended coolant life, less nucleate boiling, greater heat transfer, and improved performance. The premise of their marketing is that, by excluding water from coolant, certain benefits can be achieved. Some are 100% propylene glycol, and others are a mix of propylene glycol and ethylene glycol. EVANS WATERLESS COOLANT: OVERVIEW OF RESEARCH RESULTSĮvans offers several different iterations of their waterless coolant products. ![]()
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