Added UHMW rod to McMaster Carr cart for rudder bar spacer. Opened and inspected McMaster Carr shipment. Installed one set of parts on a master cylinder and measured spring compression at the stop. It was about 0.85 inches. The spring has a rate of 15.9 pounds/inch so the addition spring force is approximately 13 pounds. I'm going to discuss the measurements with Brian at the next EAA chapter 187 meeting. I measured the spring force of three cylinders with only the internal spring and got approximately 10 pounds. It isn't a clean measurement because the seals add friction. Researched solvent to use for cleaning brake fittings. Used MEK. Disassembled and reassembled remaining master cylinders with new seals and springs per Matco documentation. Checked flow from top to bottom port. Checked movement of shaft before pressure reached. Checked for leaks and continued movement of shaft with pressure maintained. All okay. Drained cylinders, cleaned threads and installed fittings in the orientation shown in drawings 36A and 37. Used Lactate 567 for the AN fittings. The Legris fittings had a sealant pre-applied. I really like that the Legris fittings are swivel type so you can tighten the fitting properly and then rotate it to the desired orientation. You have to compromise on tightness to get the desired installation orientation on the 90 degree AN NPT to flare fittings. Looked up Legris fitting specs. I would really like to use them for some of the other brake lines, but I think they are marginal on the pressure rating. The AN fittings are installed and I will use them and the Aircraft Specialty hoses I purchased. Looked at potential places to install another wire feedthrough in the firewall. Need to research that more and install them before riveting the top skin in place. Also considered installing nutplates to allow easy installation and removal of the pressure sensor manifold. Looked to see if I am ready to install the brake fluid reservoir. The reservoir needs to be installed after the instrument panel structure and before the top skin. Or I can crawl around under the panel and install it later.