The International Cessna^® 170 Association

For what it's worth I sprayed the inside of my filler cap with Corrosion-X and dumped in a can of Avblend at last oil change. So far no rust has
re-appeared in the filler neck or cap since. I don't know what did the trick but I'll take it.

Still getting moisture out the breather but I'm told that's normal.

Note: At annual I replaced the short rubber hose at the front of the case where the breather tube attaches. I found an accululation of congealed oil and moisture creating a greasy substance which had almost plugged the breather tube forword of the rubber hose. Might be worth a periodic check.

Lars

Seeing that you're up in the NW, ... you might consider wrapping your breather, from the elbow to the aft baffle, with insulating tape and/or firesleeve, to insulate it. With frosty air blowing into the cowl all the time, it's going to have an increased propensity to congeal like that. (And all operators should confirm their breather has a "reverse cut" or vent-hole in it behind the aft baffle/fwd of the firewall, about 10 inches from the end. This is to prevent a frozen/blocked end from creating a blockage.)
It's common and normal for the beather to drip foamy oil onto the ground after a flight. A couple teaspoons is probably normal, but it's like blood and gasoline spills.... a little looks like a lot.

Thanks for the insulation tip. I'll give it a try.

So that's what the hole in my breather tube is for! As I live and learn I had the breather tube on my list for replacement parts because it had a hole in it.

Lars