Pilot's And Copilot's Gyro Installation With Deicer Boots - Piper PA-31-350 Maintenance Manual

PIPER AIRCRAFT
T-1020
MAINTENANCE MANUAL
PILOT'S AND COPILOT'S GYRO INSTALLATION WITH DEICER BOOTS.
1. Install a test pressure gauge to the pneumatic system test gauge tap point by removing the left aft
plate at the top of the right engine nacelle.
2. At the test gauge tap point remove the cap from the tap fitting and install the test pressure gauge.
-NOTE -
An accurate gauge with a range from 0 to 20 psi with a hose long
enough to allow the face of the gauge to be easily observed is
desired The tap fitting is three-sixteenth straight thread flared.
3. Operate left engine at 2200 RPM (right engine OFF) and check if the test pressure gauge reads
6.0 psi on the test gauge. Should the reading not be as specified, shut-down the engine and remove the
forward access plate at the top of the nacelle. Adjust the normal pressure regulator of the dual regulator.
The normal pressure regulator incorporates the electrical solenoid. Loosen the adjustment screw jam nut of
the normal pressure regulator of the dual regulators in the right side of the nacelle and turn the screw
clockwise to increase pressure and counterclockwise to decrease pressure. Tighten adjustment screw jam
nut.
4. Repeat Step 3 for the right engine (left engine OFF).
5. To check the deicer system operation pressure, operate left engine at 2500 RPM (right engine
OFF). Actuate the deicer system. The test gauge should read 18.0 ± .5 psi (37 ± I in Hg).
-NOTE -
The pressure should be read just prior to completion of the cycle.
- NOTE-
Should the test gauge reading not be within tolerance,first ascertain
that the deicer boots have been pressure tested.
6. To adjust the deicer system operating pressure, loosen the locknut on the nacelle mounted dual
regulator. The deicer system pressure regulator is the regulator without the electric solenoid.
7. Repeat Steps 5 and 6 for the right engine (left engine OFF).
8. To adjust the gyro pressure setting. install a test gauge in the copilot's gyro pressure line. A hypo
needle inserted in the hose from the right side of the gyro control located under the copilot's instrument
panel and connected to a suitable pressure gauge is satisfactory.
9. Operate both engines at 2200 RPM. The test gauge pressure should read 5.5 ± .2 in Hg (2.7 + .
psi). To set the pressure, adjust the copilot's side of the pneumatic relay shutoff valve assembly by loosening
the locknut on the right side of the control and, with an Allen wrench, turn the set screw counterclockwise
(OUT) or clockwise (IN) until the desired pressure setting is obtained. Tighten the locknut.
10. With both engines operating at 2200 RPM. the pressure gauge for the pilot's gyros. located on
copilot's instrument panel, should read 5.5 ± .2 in Hg (2.7 + .1 psi). To adjust the pressure, loosen the
locknut on the bottom of the pneumatic relay shutoff valve assembly and, with an Allen wrench, turn
the set screw clockwise (IN) or counterclockwise (OUT) until the desired pressure setting is obtained.
Tighten the locknut.
11. With both engines operating at 2200 RPM. and with the deicers activated, insure that the pressure
gauge for the pilot's gyros reads 5.5 + .4 in. Hg (2.7 ± .2 psi).
36-14-01
Page 36-05
3I22
Issued:
September 2, 1981
3122