 Soot buildup and blade erosion caused by corrosive ash plagued all of the turbines.Changes to the air intake systems on the production turbine locomotives improved the quality of the air that reached the turbines, which in turn reduced the wear to the turbine blades and increased the turbine's running life.The GTELs were operated into late 1969 and the final two (numbers 18 and 26) were stored at the Cheyenne roundhouse in operating condition until being retired in February 1970.