I’ve pretty much done as much work as I feel is prudent with the side skins off. Before running more wiring, the instrument panel base needs to be installed and the inside edge of the firewall requires a bead of sealant. The side skins make up part of that firewall joint so the side skins need to be installed soon. The reason I say soon is that the instrument panel base needs to be installed before any more wiring can be installed because one end of the wiring harnesses are terminated with large connectors at the instrument panel end … this requires the wiring harnesses to be fished through wire grommets on the panel base and then routed throughout the fuselage.
However, once the instrument panel base is installed, it will add an additional level of difficulty when sealing the firewall … not to mention correcting possible issues with the fuel lines which have not yet been pressure tested. To that end, decided it would be prudent to put together a pressure testing rig at this time to check the fuel line fittings so if repairs are necessary, it will be easier now. After a couple of trips across town to obtain fittings, the 60 inches of water pressure gauge was cobbled onto the AN hardware and installed onto the gascolator.
A 60 inches of water pressure gauge and Schrader valve attached to gascolator for pressure testing the fuel lines.
There is a small leak somewhere … the pressure does drop very .. very .. very .. slowly. Although, it could be the fuel on/off valve because my initial thought was to keep the valve closed and pressure test the forward fuel line first, then aft of the fuel valve. I did not have the fuel line aft of the fuel valve caped off so there may not be a real leak just a slight bleed through the fuel. Plus the test setup which has a lot of joints may be the area leaking so will need to mix up a batch of soapy water or get some testing solution from a tire shop tomorrow.
Actually, the test pressure could be a much higher pressure because the fuel tank is not involved at this point. For testing the fuel tank once it is built, a pound or two is all you want to use which is why the 0-60 inches of water gauge was purchased. Forgot to look for my other pressure gauge while down at the southern outpost earlier in the week, so the new gauge will have to do for the time being.
For testing just the fuel lines, at least a 10 psi test would be ideal, some have used 60 psi … but I feel that is excessive and may possibly not be good for the electric fuel pump which pumps to around 5 psi. The pump is not a diaphragm type so there may not be an issue, but why take chances?