Hosed

It was a short session today in the workshop, but I was hosed from the get go. Literally, and figuratively. in accordance with a suggestion from Scott Spencer, I decided to seal the ends of the fire sleeve with RTV to prevent the fibers from wicking up oils, solvents, etc. They make a product to do this called ‘End Dip’ for this. It is frightfully expensive and only comes in quantities large enough for about 5 lifetime’s worth of airplane projects. I have a bit of extra RTV from installing the firewall, so I am using this.

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This is the Oil Cooler return line, and I let that dry while I installed the fittings for this line in the engine accessory case and oil cooler. The fittings are 90 degree elbows and were installed with the recommended permatex thread sealer. Then I could install the line.

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I still have to get some appropriately sized rubber hose to use for standoffs so that I can secure this hose to prevent chafing. I am thinking I am going to check to see if the routing is better by going under the induction tubes as the hose ended up slightly longer than it needs to be. But it fits and is certainly acceptable the way it is.

I then turned my attention to fuel lines. I started by making up a line that goes from the bulkhead fitting in the firewall that is the fuel supply from the tanks. This line goes to the ‘in’ port on the fuel pump, which is on the left side of the pump. If I was thinking when I routed the fuel lines in the fuselage, I would have researched this and put the bulkhead fitting on the left side of the firewall. No big deal, just makes for a crossover of hoses.

While I was making up the fuel hose, I was referencing the instructions so that I didn’t forget a step. I apparently didn’t read these very closely the first time around, as I got a chuckle out of the last sentence in step 6. Luckily, I didn’t have to say any unsavory words…. yet.

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After the hose was fabricated, I went to install it and found that the routing I initially chose was poor, and the hose was too short to be used for a better routing. This steel braided hose requires a fairly large radius bend as to not put too much strain on the end fittings. This meant that the routing I chose put the hose into conflict with the throttle and mixture control arms. I will have to make a new hose for this with a different routing.

Since I already had the hose made up, I decided to see if it would work for the line from the outlet of the fuel pump to the fuel injection servo input. So I went to put the output fitting into the fuel pump, and it was immediately apparent that the engine mount interferes. When we did the repair to the engine mount, we were sure to leave room for the fitting, but we didn’t think about rotating the fitting to install it. So it was time to pull the engine mount off the airplane to get better access.

I ended up deciding to take the fuel pump off, install the fitting, then reinstall the fuel pump. In retrospect, it probably would have been better to take the engine mount off the engine. But either way, it got the fitting installed. While I was back there. I got the torque wrench out and final torqued the mounting bolts for the fuel pump and safety wired. It took me, you guessed it, 3 attempts to get the safety wire right. But now, the fuel pump is final installed, torqued, safetied, and the fittings are installed.

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Unfortunately, the hose was too short to work for this application too. Oh well, it was a short section of hose, and I will keep it in the supply in case it becomes useful somewhere else. I will just take the ends off and use them on the new hose.

I ran out of time to do anything else, but hopefully we can get more lines made up and installed tomorrow and press on.

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