Today we're talking about how to properly "lay-up" (store) steam locomotive air compressors between runs or seasons. Our example compressor is one of two recently acquired by the Kentucky Steam Heritage Corp., from the Pueblo Railway Museum. It should be mentioned that on operating locomotives it is good practice to use steam cylinder oil mixed 50/50 with journal oil (aka 30wt oil). These compressors will have steam cylinder oil blown through them after they're mounted on the locomotive in sever