The old dryer was filled with yellow sludge because that is what motor oil will turn into when exposed to a lot of moisture. Odds are that your compressor was already worn out and that the trip just finished it off.
Originally Posted by opus
$150 for a Bendix AD9. You might be asking for trouble without one.
I agree. Unless you live in a dry area that doesn't freeze, I'd put an air dryer back on. Even if you do live in an area like that, your going to have to drain the tanks every day you drive it to drain the condensation and prevent the tanks from rusting internally.