Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 1091 / 1956

PAGE 1
Feb 28/07 6C21
37-00-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
GENERAL
1. Description
The vacuum system consists of 2 continuously operating engine-driven dry air pumps; 1 rotating
clockwise and 1 rotating counterclockwise. Either pump can independently support the system. Also
included are two regulators, an air inlet filter, and a manifold that connects the autopilot, pilot's attitude
indicator, cabin pressure controller, vacuum solenoid valve, and optional copilot instruments.
In S/N’s 4636001 thru 4636020 only , a vacuum gauge incorporating two red flow buttons is mounted on
the pilot's instrument panel. When both pumps are operating satisfactorily, neither flow button is visible.
The left flow button will protrude should the clockwise rotating pump fail. The right flow button will
protrude should the counterclockwise rotating pump fail. The total vacuum pressure, which is displayed
on the vacuum gauge, is normally regulated between 4.8 and 5.2 inches of mercury (in. Hg).
In S/N’s 4636021 and up , the vacuum gauge has been incorporated into the Transicoil Electronic Module
Instrument System (see 77-40-00). A transducer mounted on the rear of the forward pressure bulkhead
provides input to the Vacuum Pressure Indicator (VAC) which is co-located with the Cylinder Head
Temperature (CHT) indicator The VAC indicator provides an analog display in the 3.0 - 6.0 in. HG range.
Normal operating pressures are between 4.5 - 5.2 in. hg. or 4.8 - 5.2 in. hg, depending on the gauge
installed in the particular aircraft. Vacuum pressure may also be displayed digitally on the Quad Digital
Indicator/Enhanced Digital Indicator by pressing the function switch next to the analog display.
If aircraft is equipped with a pneumatic deicing system, refer also to 30-10-00.
2. Troubleshooting
See Chart 1.