988
PIPER
SENECA
II
SERVICE
MANUAL
COMPOUND
GAGE
PULL
26
TO
28
INCHES
VACUUM
PRESSURE
GAGE
NOTE:
OPEN
BOTH
SERVICE VALVES
(COUNTERCLOCKWISE) ONE
TURN
EVAPORATOR
ASS' Y
Figure 14-28. Evacuation Hookup
SCHRADER
VALVE
System Vacuum
Temperature
°F.
27.99
COMPOUND
GAUGE
28.89
READING
IN
INCHES
29.40
OF
MERCURY
VACUUM
29.71
29.82
29.88
NOTE
For
each 1,000 feet
of
elevation above sea level, the compound
gauge reading will be about one inch lower, numerically.
The following steps should be
of
help when performing this operation.
100
80
60
40
20
0
a. Remove access panel at the rear
of
the cabin
to
gain access
to
the Schrader service valves.
CAUTION
Ascertain
that
all system pressure
is
released before attempting the
evacuation. (Refer to Paragraph 14-97.)
Reissued:
10/11/79
3D9
ACCESSORIES
AND
UTILITIES
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