Vacuum System - Piper WARRIOR III PA-28-161 Pilot Operating Handbook

PIPER AIRCRAFT CORPORATION
PA-28-161 WARRIOR III

7.17 VACUUM SYSTEM

The vacuum system is designed to operate the air-driven gyro instru-
ments. This includes the directional and attitude gyros when installed. The
system consists of an engine driven vacuum pump, a vacuum regulator, a filter
and the necessary plumbing.
The vacuum pump is a dry-type pump. A shear drive protects the pump
from damage. If the drive shears, the gyros will become inoperative.
A vacuum gauge, mounted on the far left instrument panel, provides a pilot
check for the system during operation. A decrease in pressure in a system that
remained constant over an extended period may indicate a dirty filter, dirty
screens, possibly a sticky vacuum regulator or leak in the system (a low
vacuum indicator light is provided in the annunciator panel). Zero pressure
would indicate a sheared pump drive, defective pump, possibly a defective
ISSUED: JULY 1, 1994
CIRCUIT BREAKER PANEL
Figure 7-13
DESCRIPTION & OPERATION
REPORT: VB-1565
SECTION 7
7-13