my class a 2006 Georgetown with a F53 dive line power steering box started to leak at the end of a 900 mile trip. I ruled out lines and pump..thinking the steering box adjuster might be leaking I found a 1/4 in round hole below it..looking at rebuilt ones on line it appears there's a plug that has fallen out. Any one have this happen and where can they be purchased. I don't see them in a box seal kit