Persistent Intake Leak

[Chris Iriarte]

Well, I took mine apart and didn't find a crack. However, when I torqued the collar down (without tightening the sump end) the tube could still move back and forth. Is it possible the flange has worn so thin that it's not making a good seal?

Chris

[rocket]

Give the coller a good look I have seen them distorted, think bowed, from bolt hole to bolt hole. I've flattened them in a press and a vice.

Rocket

[Chris Iriarte]

Ach, didn't think of that.

[gliderman]

Also lycoming made two flanges: a thick one and a thin one. the thick one is usually found on higher HP engines. it could be that somebody grabbed a thick one and used it with your thin flanged intake pipe

wish I had a picture....

[rocket]

Now I didn't know there were two types/thicknesses. I have seen a number of them miss installed where the flange of the pipe was not properly seated in the collar. I can usually tell just by looking.

I snug up both bolts and then slide the tube around making sure it is within its depression and then tighten a little at a time switching back and forth to keep it all even. Then I tighten the hose clamp on the other end.

I have to pull the two aft intake tubes to get the nose gear assembly off or on each time I switch from floats to wheel gear or back. Really thought about just pulling the olio assembly and just leaving the works bolted on but its about a wash when all is said and done.


Rocket

[Chris Iriarte]

Looks like I have two things to check then. I put a straight edge on the tube flange but don't know why I didn't check for "taco-ing" on the collar, plus it has a part number stamped on it so I can check that as well.

update: 3 of my 4 collars (flanges in the PC) ar stamped 69009 (or maybe 60069, depending on which way is up) and neither number is in the O-320 catalog!

update #2: The collar/flange had a very slight but very definite bend to it. Flattened it out in the press and everything's tight … hopefully fourth time's the charm!

chris

[Chris Iriarte]

Just thought I'd bump this with an update to share the results. The collar ("flange" per the parts catalog) did have a slight bend ... couldn't see it with the eye but when I put it on a flat surface you could rock it side to side. Straightening it out in a press did the trick ... no more leak!

Chris