Hrs: 7

Redo inside breather lines

As mentioned in the previous post I was unsure about applying Loctite 577 to the thread of the flared fittings. After some more research it’s obvious that no sealant is required so I decided to remove the inside breather lines and to redo them. One other reason to redo them is that the flares on the inside breather lines were not formed nicely.

I started with 1/4 inch 5052 aluminium tube of 15 cm and added a flare. Because I was not happy with the result of the flaring tool that I purchased at Oshkosh last year I did some review and ordered the Rolo flair tool. This tool leaves almost no tool marks and creates a much better flare.

Flares done:

Then I created a 180 degrees bend as tight as possible:

But the radius of the tool was too large, so I created a wooden mold to tighten the bend:

And after cutting the longer part to the correct size I drilled a #40 hole with help of another wooden mold:

New inside breather line is ready:

And to verify how a flare looks like from the inside a created a small test piece, just for informational purposes:

I adjusted the inside breather line so that the distance to the rib and top is about 5-6 mm.
With help of a crowfoot I torqued the B-nut t0 50 inch/lbs.

I mixed some sealant to apply on the outside of the fitting to prevent that the B-nut loosens, I also installed the outside breather lines to seal the B-nut with the same batch of sealant, this makes it a bit more difficult to rivet the backplate but it’s doable: