On 28-Oct-2003, "Jay Honeck" wrote:

How would you recommend going about doing that?


I really don't know how easy it is to determine the presence of suitable
suction at the end of a vacuum tube just by putting your finger over it, but
certainly your A&P should have a vacuum gauge that will remove all doubt.

There should be two hoses attached to the back of the DG. One (the air
outlet) comes from the vacuum regulator and the other (the air inlet) goes
(probably through a "T" connector) to the filter.

First remove the air inlet hose. With the engine running (vacuum gauge
registering) check if there is suction at the inlet port to the DG (where
you just removed the hose). BTW, if the DG now seems to be working, the
problem is an obstruction on the inlet side.

Then remove the air outlet hose from the DG. Check if there is suction at
the end of this hose.

If there is suction in both places your DG is bad. The airflow is not
spinning the gyro.
If there is no suction at the air outlet there is a leak or obstruction
between the regulator and the DG.
If there is suction at the air outlet but not at the air inlet your DG is
bad, but it may just be a relatively simple internal obstruction.

--
-Elliott Drucker