[Bobcat]

Patrick .... Nylon seals ok if there are irregular surfaces , nicks etc ..... for a while . As long as you don`t undo the connection and then reuse the Nylon "0" ring/flat seal . It doesn`t have as much memory as some other materials and tends to retain the "pattern" of the surface it was mated to . A lot of the race teams I am familiar with use both Nylon and fiber , but they also use a seal only once .... as seal manufacturers recommend !
One of the Divisions of the company I worked for was Parker Seal in Salt Lake City ..... probably one of the largest makers of seals in the world , and I worked with applications engineers there more than once on various projects . Yes , Nylon will work , but don`t try to reuse it .... or any other gasket/"O" ring . You might get away with it once or twice , but it will eventually leak .
BTW , my experience comes from the field and racetrack ... not an article .