THE NEW PIPER AIRCRAFT, INC.
PA-32-301FT / 301XTC
MAINTENANCE MANUAL
PAGE 2
Jun 1/03
3K6
37-10-00
3. Vacuum
Pumps
Two (2) engine-driven dry-air pumps are mounted on the accessory section at the rear of the engine.
Each vacuum pump is a rotary vane, positive displacement type. These units consist of an
aluminum housing, a carbon rotor and carbon vanes. They are driven by means of a coupling mated to
an engine-driven gear assembly.
A. Inspection (See Figure 1.)
The vacuum pump(s) feature a wear indicator inspection port on the back cover which allows direct
observation of pump vane wear. Beginning at 500 hours time-in-service, and each 100 hours
thereafter, remove the inspection port plug and observe vane wear as shown in Figure 1.
(1) As the vanes wear, they slide outboard in the vane slots in the rotor.
(2) When the portion of the vane that can be observed in the inspection port covers less than half
of the inspection port, replace the pump.
B. Removal
(1) Remove engine cowling. (Refer to Chapter 71.)
(2) Loosen hose clamp and remove hose from pump fittings.
(3) Remove four retaining nuts, lock washers and plain washers used to secure pump to engine;
then remove pump.
Vacuum Pump Vane Wear Inspection
Figure 1