FYI Interval for cleaning the breather tube on a CubCrafters Carbon Cub FX-3 with Lycoming 363i

[Neal]

The guidance which I believe comes from CubCrafters is to clean the breather tube inside the exhaust pipe with the provided wire brush at each oil change. I cannot stress enough that is too much time between cleanings. I do mine about every 10 hours, if not more frequently, and today prior to flight I decided to do mine and it was clogged.

Clean it frequently!

P.S. I don't know the official name for that tube we clean out. And when I was at CubCrafters for the 10 hour they had theirs on the end of a drill for even better cleaning capability.

 

[Tsquared]

When I took delivery of my FX3 I was told to clean that tube every 5 hrs, 10 hr at the most. On the few times I’ve exceeded 10 hrs between cleanings mine has been seriously junked up.

Protip - after cleaning the tube, clean the brush with some Avgas and a screw driver tip.

 

[Neal]

Here is the cleaning brush from CubCrafters:

7353T12-Hand-Held LT Breather Tube Brush with SS Bristles

store.cubcrafters.com

I think the important part is this is a tube brush vs. rifle cleaning rod. We don't need bristle brushes coming off inside that tube

I did a quick search on Amazon for tube brushes but if I needed another I'd just get the one from CubCrafters with other parts such as a new ignition backup battery when that time comes, etc.

 

[Neal]

Is this breather tube specific to CubCrafters or do other engines such as the IO-360 have it?

 

[Neal]

A thought comes to mind in that if you intend to fly across the country such as when I brought my FX-3 home you should have this cleaning brush on board. It was 28 hours of flying for me to bring it home.

 

[Tsquared]

Agreed. And when I flew mine home to MN I cleaned it after every other leg. approx 2.5 hr legs. 11.5 hr tt

 

[Hunter]

Are y'all taking the cowling off and removing the hose during each cleaning? When I took delivery of the plane, I was told to just stick the pipe cleaner "up there" and loosen the buildup. Is the concern that you could poke it up too far into the hose?
I've read the service instructions released by cubcrafters, but I'd also like to know if cleaning in a pinch without a full inspection is possible.

I've been running into elevated oil pressure lately, and I'm wondering if this could be a result of buildup.

 

[Neal]

No cowling off, I use a flashlight up the exhaust to find the breather tube and use the tube brush to ensure it's not obstructed and try to clean the soot out as good as I can. I don't think the tube brush is long enough to go "too far" but you'll feel the constricted area if you have build up.

What oil pressure are you seeing? Last night I flew and watched it carefully post oil change and I was at around 81 psi for the flight. I'm using Aeroshell 15W50. What oil is in your engine?

 

[Tsquared]

I’m just pushing the cleaning brush up the tube a few time until I feel any crud loosen up. you can’t push the brush up very far and you will hit enough resistance that will indicate it’s far enough.

I’ve never pulled the cowl or tube off to clean it.

 

[Hunter]

No cowling off, I use a flashlight up the exhaust to find the breather tube and use the tube brush to ensure it's not obstructed and try to clean the soot out as good as I can. I don't think the tube brush is long enough to go "too far" but you'll feel the constricted area if you have build up.

What oil pressure are you seeing? Last night I flew and watched it carefully post oil change and I was at around 81 psi for the flight. I'm using Aeroshell 15W50. What oil is in your engine?

During the run up high 80s (87-89). With oil temp in the green mid to high 80's (85-87)

I use 15W50 and recently did a fresh oil change.