C.
The gyros themselves act as a limiting device to keep the vacuum power applied from exceeding safe
levels.
— Note —
If the panel gauge has been checked and found OK and the vacuum gauge reading
does not repeat within the range of 5.0 ± .2 inches of mercury then the regulating
valve should be changed. Observe the usual precautions for maintaining system
cleanliness to avoid premature pump service.
VACUUM GAUGE.
The suction gauge is mounted to the right of the right control column, except on S/N 44-95001 and up the
vacuum gauge is located on the upper right hand side of the instrument panel. This gauge is calibrated in inches
of mercury and indicates the differential pressure across the pilot's attitude gyro. As the system becomes clogged
or lines obstructed. the gauge will show a decrease in pressure. Do not reset the regulator until the filter and lines
have been checked. The gauge also has two red malfunction indicator buttons. Whenever vacuum is not available
from one of the vacuum sources. the appropriate red button appears at the face of the gauge.
REMOVAL AND INSTALLATION OF FACE MOUNTED INSTRUMENTS.
Since all instruments are mounted in a similar manner. a description of a typical removal and installation is
provided as a guide. Special care should be taken when any operation pertaining to the instruments is performed
1. Remove the face panel.
2. With the face panel removed. the mounting screws for the individual instruments will be exposed. Remove
the connections to the instruments prior to removing the mounting screws of the instrument to be removed.
— Note —
Tag instrument connections for ease of installation.
3. Installation of the instruments will be in reverse of removal. After the installation is completed and before
replacing the instrument face panel, check all components for security and clearance of the control column.
VACUUM REGULATOR VALVE.
Two vacuum regulator valves that contain filters are incorporated in the system to control vacuum pressure to
the gyro instruments. A manifold check valve assembly assures vacuum if one engine or pump should fail.
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
3 7 - 1 4 - 0 0
Page 37-07
Revised: May 15, 1989
2K14
PIPER AIRCRAFT
Summary of Contents for SEMINOLE PA-44-180
Page 38: ...CHAPTER DIMENSIONS AND AREAS 1B14...
Page 49: ...CHAPTER LIFTING AND SHORING 1C1...
Page 53: ...CHAPTER LEVELING AND WEIGHING 1C5...
Page 58: ...CHAPTER TOWING AND TAXIING 1C10...
Page 62: ...CHAPTER PARKING AND MOORING 1C14...
Page 65: ...CHAPTER REQUIRED PLACARDS 1C17...
Page 70: ...CHAPTER SERVICING 1C22...
Page 98: ...CHAPTER STANDARD PRACTICES AIRFRAME 1E2...
Page 108: ...CHAPTER ENVIRONMENTAL SYSTEM 1E12...
Page 189: ...CHAPTER AUTOFLIGHT 1H21...
Page 192: ...CHAPTER COMMUNICATIONS 1H24...
Page 202: ...CHAPTER ELECTRICAL POWER 1I10...
Page 228: ...CHAPTER EQUIPMENT FURNISHINGS 1J12...
Page 233: ...CHAPTER FIRE PROTECTION 1J17...
Page 238: ...CHAPTER FLIGHT CONTROLS 1J24...
Page 304: ...2A18 CHAPTER FUEL...
Page 325: ...2B17 CHAPTER HYDRAULIC POWER...
Page 357: ...2D1 CHAPTER ICE AND RAIN PROTECTION...
Page 414: ...CHAPTER LANDING GEAR 2F13...
Page 479: ...2I6 CHAPTER LIGHTS...
Page 488: ...2I16 CHAPTER NAVIGATION AND PITOT STATIC...
Page 503: ...2J7 CHAPTER OXYGEN...
Page 524: ...2K6 CHAPTER VACUUM...
Page 535: ...2K19 CHAPTER ELECTRICAL ELECTRONIC PANELS AND MULTIPURPOSE PARTS...
Page 546: ...INTENTIONALLY LEFT BLANK PA 44 180 180T AIRPLANE MAINTENANCE MANUAL 2L6 PIPER AIRCRAFT...
Page 547: ...2L7 CHAPTER STRUCTURES...
Page 582: ...CHAPTER DOORS 3A18...
Page 593: ...CHAPTER STABILIZERS 3B8...
Page 604: ...CHAPTER WINDOWS 3B22...
Page 611: ...CHAPTER WINGS 3C10...
Page 624: ...CHAPTER PROPELLER 3D1...
Page 643: ...CHAPTER POWER PLANT 3D21...
Page 667: ...CHAPTER ENGINE FUEL SYSTEM 3F1...
Page 681: ...CHAPTER IGNITION 3F16...
Page 712: ...CHAPTER ENGINE INDICATING 3H1...
Page 730: ...CHAPTER EXHAUST 3H19...
Page 734: ...CHAPTER OIL 3I1...
Page 743: ...CHAPTER STARTING 3I11...
Page 755: ...CHAPTER TURBINES 3J1...