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Lycoming intake hose replacement

I was hoping I could leave the cylinder side alone for this, but maybe that was wishful thinking

Not possible, pipes have to come off. I usually slit the hoses with a razor knife to avoid putting unnecessary loads on the stub pipe that’s crimped into the sump. Flange gaskets don’t last forever either so it doesn’t hurt to change them every couple years. You’ll need new lock washers too. I would check the mating surface of the flanges for flatness while you have them off, sometimes they get a little bow shaped and can be sanded back to flat.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
No silicone hoses if carb'd, though great for F.I. carrying just air.

Right? Hence Ross's different parts for his improved gasket seal kits.
 
Just replaced mine

My hoses had cracks similar to yours and I had fuel stains up by the flange, indicating the gaskets were leaking. The A&P I use for advice and condition inspections told me to replace the gaskets and hoses. I thought about buying the SDS kit - it looks like a really nice product and has great reviews, but I didn't (frugal side of me won).
My experience: The back bolt/screw for the flange on cylinders #1 and #3 (right side) are hard to get to (probably why some have replaced with allen head cap screws). A universal joint socket worked well for me. My hoses and flange gaskets came off easily. There was a lot of "gunk" inside my tubes. I'm guessing it was old fuel, oil, carbon residue. I cleaned the tubes in a parts washer. The flanges also went in the parts washer.

While you have the tube assembly removed - take the opportunity to give that area a "good look" for any other issues.

During installation, ensure that the flange end of the intake tube elbow fits completely in the recess of the flange - it must lay flat against the cylinder.

As others have noted, use new lock washers. Note that there are torque settings for both the bolts and the clamps on the hose coupler.

Use torque seal on the bolts and check them after flying a few hours and then periodically to be sure they are not backing off. (you can also watch your EGTs for an indication of a leak)

Download an overhaul manual. (I used XP360_OverhaulManual) It has exploded views, torque settings, and installation instructions.

Hope you find this helpful -
 
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