Oil hose improvement

Since spare time is rare these days, when I get to the hangar I try to focus on small improvements that I can finish in a few hours. I leave the gear rigging, wing rigging and weight & balance for when I will have a few hangar days in a row in front of me.

During my last visit to the hangar, I focused on improving an oil hose I wasn't too happy with: the hose going from the top of the oil separator to the engine breather port. When I installed it, I unintentionally induced a little bit of twist into it:

The above hose end setup forced quite a bit of bending in the hose as well. Switching to a 30 deg hose end helped in reducing the bending while still giving proper clearance to access the oil dipstick:

I made sure this time there was no twist in the hose and it turned out better.

I am about to seal the gap between the fuse side panels and firewall with RTV. That's the reason behind the green masking tape you see in the pictures above.

Next small project: change the oil sump fitting from the swivel type to straight type fitting. 

Hoses replacement

It was much longer than I anticipated, but last week-end, I finally completed the rebuild of FWF hoses. Here is a picture of all the old hoses with the firesleeves that I am also replacing:

I started working on the new firesleeves today. As mentioned in my previous post, I am protecting more hoses than before. I first used a pair of cissors to cut them to length but found it made a better job using an x-acto. Here are the main ones:

I then made a mix of RTV sealant with MEK to seal the ends. 50/50 gave me a good result:

I then transferred the mix into a smaller cup and dipped each firesleeve end in it. Here is what it looks like:

I am getting close to being able to put the engine back on the fuse. I worked quite a bit on my firewall a few weeks ago and installed/changed many nutplates. The fuselage is ready to receive the engine back:

Next step is to install the firesleeves and reinstall the hoses back on the engine. Stay tuned!

Back to work

It's been a while since my last post. Went on vacation, got sick and slowly recovered. I can finally resume my work on the Pitts : )

Been working quite a lot these days to replace all the hoses FWF. I checked the logbook and my hoses were all 10+ years old so I decided to change them. The hoses are all steel braided and hose ends are all Aeroquip 816 type or equivalent. I wish I could afford all brand new hose ends and fittings but they're just too expensive so I'm only changing the steel braided hoses and reusing the hose ends.

First had to purge the oil from the engine and start removing hoses. Some hoses were "fire protected" with a fiberglass sleeve attached with lacing and tie-wraps:



I didn't find this very smart for two reasons. First, plastic tie-wraps will quickly melt in case of fire and second, since there is no silicon wrap around it, it doesn't prevents contaminants like oil and fuel to soak the fiberglass and turn it into a fire hazard rather than a fire protection. As you can imagine, I bought proper firesleeve material and will replace the old fire-enhancing sleeves...

For each hose, I carefully remove the hose ends using special bench vise jaws and a wrench:



Then I cut the new hoses using a small metal cutting saw which allows nice clean cuts which makes my job easier later to reinstall the hose end:



After that I reinstall the hose ends using the technique recommended in this EAA video.

Doing this for all hoses is time consuming. I did all the oil hoses already and just started removing fuel hoses. I realized that due to lack of lubrication, fuel hoses get much stiffer over time than oil hoses.

I'm about 50% done now. Will post an update once complete!