Static line doesn?t work-help please

[9Abuilder]

I?m completing a 9A. Instrument panel has all AFS products: 5600 EFIS, Auto Pilot, Comm. Radio, Intercom, and stand-alone AOA. Panel also has a Dynon D-6 back-up screen. Pitot tested great-all working as expected. My static system is another issue. I use a glue syringe to test in very small puffs of air. Hooking up the static line at the panel, the D-6 and auto pilot work fine. Hooking up the static line at the ADHARS and the 5600 works fine. Hook up the test at the rear ?T? connection, which joins the two static ports, the ADHARS, and the static line running to the panel, and I get nothing. Covering one port and blowing air in the other port and I get nothing. Have disconnected the static line running to the panel at the ?T? connection and blown air backwards to the static ports. Air comes out both ports, meaning no clog in the line. AFS tells me everything should work, but it doesn?t. What am I doing wrong? Anyone had a similar experience, with a happy outcome they could share?

[rvbuilder2002]

A static system never has positive pressure (above ambient baro pressure) so a test is typically done by pulling a slight vacuum on the system.

When there is two static ports one must be blocked while pulling the vacuum on the other (otherwise it acts as a large leak).

The result you get implies a large leak so you need to start isolating portions of your system to identify where it is located.

Start with connecting to the line going fwd to the D6 and see if pulling a vacuum on it holds an altitude a couple thousand ft above your ground level.

If it doesn't then the leak is somewhere along that line of the connections at the instrument panel.

[9Abuilder]

Scott,
I tested the system by first covering one port and applying vacuum pressure from the syringe, with no success. The next thing I did was to replace all lines and connectors behind the panel running to the D-6 and the auto pilot. No difference. Would the plastic ?T? connector running a smaller line to the AOA cause any issue? I did not mention before that I am using SafeAir plastic lines and connectors, as well as their static ports. Any additional ideas?QUOTE=rvbuilder2002;1339882]A static system never has positive pressure (above ambient baro pressure) so a test is typically done by pulling a slight vacuum on the system.

When there is two static ports one must be blocked while pulling the vacuum on the other (otherwise it acts as a large leak).

The result you get implies a large leak so you need to start isolating portions of your system to identify where it is located.

Start with connecting to the line going fwd to the D6 and see if pulling a vacuum on it holds an altitude a couple thousand ft above your ground level.

If it doesn't then the leak is somewhere along that line of the connections at the instrument panel.[/quote]

[BillL]

You know best what equipment you have and hoe it is connected, but my Garmin parts had some odd characteristics when checking static. The installation manual had notes about checking. Reading them is important as there may be reasons to check two ports simultaneously for the AOA.

I had leaks. and started small. Just the line from front to rear. I pulled the vacuum with a syringe and measured with a tall manometer. I used vacuum bagging sticky tape to cover the external ports but I think good packing tape will work too. Just be sure it has good contact.

Progressive testing was done - rear to front. Isolating known sections and mentally marking them as sealed.

Issues found: Garmin pitot has an internal leak - noted in manual. 75% if my factory fittings leaked at the threads to the avionics. The pre-applied sealant did not seal well. The tubing is stiff and one joint was not fully engaged.

The largest problem area was my test equipment. I tried using the white, barbed vacuum fittings sourced from local auto parts - they all leaked. They had manufacturing split lines don't allow good sealing. Even my syringe leaked some internally, so vice grips were used to pinch and hold the tubing. You might want to test the equipment first so you can get a feel for what a small leak or a sealed system looks like.

Hardware store small brass barbs worked well, as did their push on fittings (like safe air).

If you have or can get some vacuum bagging sticky tape is was a big help as it cam be pressed to make a perfect seal.

Good luck!! Getting this done was very helpful when the official test time came.