Vacuum System Failure - Cessna 172R Pilot Operating Handbook

If low voltage light illuminates again:
Alternator-- OFF.
A CAUTION
WITH THE ALTERNATOR SIDE OF THE MASTER
SWITCH OFF, COMPASS DEVIATIONS OF AS
MUCH AS 25° MAY OCCUR.
Nonessential Radio and Electrical Equipment -- OFF.
Flight -- TERMINATE as soon as practical.
VACUUM SYSTEM FAILURE
I L e ft Vacuum or Right Vacuum Annunciator Light (L VAC R)
Illuminates.
A CAUTION
IF
VACUUM
IS NOT
WITHIN
NORMAL
OPERATING LIMITS,
A
FAILURE
HAS
OCCURRED IN THE VACUUM SYSTEM AND
PARTIAL
PANEL
PROCEDURES
MAY
BE
REQUIRED FOR CONTINUED FLIGHT.
1. Suction Gage
CHECK to ensure vacuum within normal
operating limits.
3-12
Nov 3/97
SECTION 3 CESSNA
EMERGENCY PROCEDURES MODEL 172R