Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 533 / 881

ADJUSTMENTS TO VACUUM REGULATOR VALVE. (Refer to Figure 37-2.)
1. Remove nacelle cover(s), straighten adjustment screw lock tabs on valve.
2. Adjust regulator screw in accordance with the direction desired, run engine to check results.
— Note —
With one engine operating at 2000 RPM and the opposite engine at idle or off, set he
vacuum regulator at 5.0 + .2 inches of mercury. Repeat for opposite engine. After
adjusting regulators check vacuum is within limits with both engines at 2000 RPM.
3. When the recommended vacuum indications are attained, bend tabs to lock adjusting screw, restore aircraft
to airworthy condition.
REMOVAL AND REPLACEMENT OF REGULATOR VALVE.
1. To remove the regulator valve, disconnect the two lines, remove the mounting nut and remove the valve.
2. Replaced regulator in reverse order given for removal. Check complete vacuum system for proper option.
VACUUM PUMP.
The vacuum pump is of the rotary vane, positive displacement dry type. This unit consists essentially of an
aluminum housing containing a tempered sleeve in which an offset rotor, with moving blades is incorporated.
This assembly is driven by means of a coupling mated to the engine driven gear assembly. A pump is mounted on
the accessory section of each engine. The pumps differ to account for engine rotation, the starboard engine
utilizes a clockwise pump, the port engine utilizes a counter clockwise pump.
REMOVAL AND INSTALLATION OF VACUUM PUMP.
1. Remove the top portion of the engine cowling.
2. Disconnect the two hoses at the pump.
3. Remove the four mounting nuts, lockwashers and plain washers, and withdraw the pump from the engine.
— CAUTION —
THE ONLY DRY AIR PUMP MOUNTING GASKET AUTHORIZED AND
APPROVED FOR USE ON AIRBORNE DRY AIR PUMP IS THE AIRBORNE
GASKET B3-1-2, PIPER PA RT NUMBER 751 859. USE OF ANY OTHER
GASKET MAY RESULT IN OIL SEEPAGE OR LEAKAGE AT THE
MOUNTING SURFACE. TORQUE THE FOUR MOUNTING NUTS TO 50 -
70 INCH-POUNDS.
4. Reinstall the pump in reverse order of removal.
5. Install the fittings with a torque of 95 to 110 inch-pounds.
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
3 7 - 1 5 - 0 1
Page 37-08
Revised: May 15, 1989
2K15
PIPER AIRCRAFT