Getting ready for a 800 mile trip to lake city, colorado and was worried about my fass quitting. It has had a squelling sound 75% of the time and have done lots of research but nothing led to what I found. One of the plastic brush caps had backed off 3/4 of turn and that was the cause of the sheep moaning noise that drove me crazy. I pulled both brushes out and cleaned the guides with q-tips and alcohol and used a scoth brite pad to polish up the contacts a bit. I replaced both filters today and am ready for a quiet trip to colorado.

 

Note to self: Good info.......file for future reference.

 

ALSO might want to state that that you have the older motor that has the servicable brushes. The newer unit (about late '05) have a motor that the brushes are internal.

BUT that is good to know...thanks for letting other know......

 

Good news, mine started doing the same thing recently too. Definitely find the time to fix it, that sound is awful.