Brake lines

Yeah I know it's been a long long time since I posted! Progress has been slow lately. Among other reasons, the commute to the hangar is a factor that doesn't help in winter time. Just to give you an idea, here's the view I have through the hangar window:

Not a time to fly a Pitts.

The long time readers of my blog will remember that I rotated my brake calipers back. I took a pause from the wing rigging exercise to work on re-routing the brake lines which accomodate the new caliper location (see original post here). I hesitated between leaving the original 45° AN823 fitting on the calipers or put a straight AN816 nipple. Wherever access allows it, I prefer installing AN816's over angle fittings since they can be torqued properly without wondering about the fitting orientation.

I was happy to find that I had proper clearance with the wheelpant caliper cover. I therefore installed the straight fittings and rerouted the lines accordingly:

Once all the couplings secured, I pumped brake fluid with a car oiler from the bottom up using the procedure recommended on the Grove Gear website. It was the first time I filled a brake system so I was worried about getting spungy brake pedals. Throughout the process, I looked carefully through the 1/8" ID plastic tube connected to the oiler to ensure that no air bubbles were getting pumped. The brake pedals ended up being quite hard : ) Patience paid off.

Finally I had to cut a notch in the wheelpants to properly clear the fitting. 

Next task is to change a few hose ends I'm not happy with in the inverted oil system. I also want to properly seal the gaps between the edges of the firewall with the forward fuselage panels.

Electrical + Master cylinders + Preparation for wings

Been a while since my last post, but I have been pretty active on the Pitts over the last month.

Electrical system

My objective was not to redo the whole electrical system although it wasn't exactly what I wanted. I replaced damaged terminals, replaced wires that had more than one splice, etc. I was surprised to find that my fuel boost pump wires were not protected (!). I fixed what I couldn't resist to fix, but I keep the revamp of my electrical system for another time and focus on the reassembly.

The old wiring was a little hairy so I made nice bundles with lacing like my friend François. One day I will make a new instrument panel with digital oil temp/pressure and fuel pressure. I don't really like the idea of having a hoses with pressurized fuel and oil going aft of the firewall, but I will keep this as is for now.

Master cylinders

While my fuselage was being welded last summer, I took the master cylinders home and changed all the o-rings. It was a good thing since they were pretty dried up. In the process of doing this, I realized the roll pins that hold the spring in place were not in good shape so I ordered new ones (see item #16 below).

I recently pulled back the box with the two master cylinders and reinstalled them on the airplane. It took a few adjustments to ensure proper geometry since the attachment points were replaced. The old bolts were secured with AN365 lock nuts which is not per AC43.13 for elements in rotation. I therefore replaced them by drilled bolts with castle nuts and cotter pins. I didn't change the brake hoses, but keep this on my list for next winter!

Preparation for reinstallation of wings

One night after work I came to the hangar and realized I was out of things to do on the fuselage. After more than 18 months of on/off work, I must admit it was a strange feeling! I decided to make a small plan to prepare to put the wings back on. Replacing the AN665 clevis hardware since the old one was getting corroded was part of it:

Since the removal of the top wing had been difficult with only 2 guys, I decided to plan for at least two other people to help me out to reinstall it: two holding the tips while one putting the bolts on the cabane...