After finding black engine oil in the air I bled from the rear bleed port and in the air dryer, it seems obvious it's time to replace the engine mounted air compressor. After I replace the compressor and air dryer cartridge, what action should I take to remove oil from the air lines? Blowing solvent through the line from the dryer to the rear bleed port while it's disconnected seems innocent enough since residual solvent won't find its way into any Norgren valves or other critical components to swell "O" rings, but what if I find oil in other lines? Do I stand a chance of making the potential problem of gummed up valves worse by attempting to clean oily air lines? Would you experts out there just blow clean dry air backwards through disconnected line segments or leave bad enough alone and just watch for oil at the valve exhaust ports? I would anticipate that engine oil might make Norgren valves sluggish in cold weather or cause the rubber rings to swell and stop the shuttle valves altogether, but what other problems are likely if the oil has gotten past the air dryer? How much of a nightmare may I be facing?

Is there enough cost difference to warrant shopping for a heavy compressor at a local truck parts shop instead of having one shipped from Prevost Parts? Thanks for any answers or comments you might have for a newbie who is about to get a comprehensive air system education.