IO-240B Exhaust Breakage

[n85ae]

Thought my engine was sounding a little clacky at idle, and not quite right. So decided to
drop the exhaust to check the gaskets, and flanges. Glad I did, found a cracked pipe on
CoPilot side rear (covered by the clamp strap), and a broken Flange on Pilot side rear

None of this was noticeable until I unbolted it and it quite literally fell apart ...

Might be a good idea to add "Drop and Inspect Exhaust" to your IO-240B Annual ... None
of these breaks were noticeable with the exhaust mounted.

Jeff

Here's a scary break, that was completely invisible before disassembly

24103

Notice the Break is completely covered by the strap.

24104

This flange looked fine, but fell into two pieces when the nuts were removed.

24105

Can see the weld on all these flanges does not completely encircle

24106

[DesertFox4]

Good catch Jeff. Knowing your aircraft is so valuable. If something sounds different, investigate.

[PapuaPilot]

Wow, great find!

Often cracking like this happens from installing something that doesn't aligned right by forcing parts together, tightening all the clamps and risers. I learned this from working on TSIO-520 Continental engines in the Cessna TU-206. During inspections we always tested these exhaust systems for cracking by applying low pressure air from a vacuum cleaner hose into the exhaust outlet. You spray all the joints with a soapy water solution and look for bubbling. I would recommend doing this rather than dropping the exhaust. If you see excessive bubbles then you will want to start opening up the clamps and dropping the exhaust.

[airlina]

Thanks for posting this Jeff, and Phil great tip on pressure testing, I am going to give that a try . Bruce N199CL

[n85ae]

Thanks Phil - That's a great idea about the shop vac and soapy water. Would for sure unbolt the plates
at the slip joints though. Maybe not the flanges at the cylinder head. Very possible to get bubbles at
a slip joint and not know if it was a crack or the joint ...

My inclination is to pull the plates. It's pretty simple, and would give you the ability to see where that pipe
is swaged, since that's where mine started cracking.

I got 17 - 18 years on it, so I'm not completely surprised to find a problem. I will for sure be very careful
when I put it together and follow your advice to avoid any stresses as it goes together. That seems very
good advice. I don't recall at this point how hard it was to put together, I don't think it was very difficult
but who know's I was more ambitious then ...

Making the entire thing more alarming, is the blue stain under the fuel pump. Since my engine driven driven
pump is weeping from right at the low pressure adjust, so it's off to the shop for Inspection/Repair as well.

Broken Exhaust + Fuel Leak = BAD NEWS.

Don't skip over stuff on those inspections ...

Jeff





Wow, great find!

Often cracking like this happens from installing something that doesn't aligned right by forcing parts together, tightening all the clamps and risers. I learned this from working on TSIO-520 Continental engines in the Cessna TU-206. During inspections we always tested these exhaust systems for cracking by applying low pressure air from a vacuum cleaner hose into the exhaust outlet. You spray all the joints with a soapy water solution and look for bubbling. I would recommend doing this rather than dropping the exhaust. If you see excessive bubbles then you will want to start opening up the clamps and dropping the exhaust.