Piper Cherokee Six Service Manual page 685

PIPER CHEROKEE SIX SERVICE MANUAL
989
COMPOUND
GAGE 50 P.S.I.
PRESSURE GAGE
SCHRADER VALVE
CLOSED
H
SCHRADER VALVE
MANIFOLD
GAGE SET
REFRIGERANT
OPEN TO 50 P.S.I.
EVAPORATOR ASS'Y
THEN CLOSE
Figure 13.5. Leak Test Hookup
NOTE
Evacuate system prior to leak check.
13-10. LEAK CHECK - METHOD I.
a. Connect the manifold gauge set into the system and determine if there is any
refrigerant in the system. A minimum of 50 psi refrigerant pressure in the system is needed
for leak detection. (Refer to Figure 13-5.)
b. Purge the hoses of air by allowing some refrigerant to escape from the connections
at the service valves. Then tighten connections at the service valve.
c. Close the low side manifold valve and open the high side manifold valve.
d. Open the refrigerant container service valve and allow the pressure at the low side
gauge to reach 50 psi at which time close the high side manifold valve.
e. Close the refrigerant container service valve and remove the hose if no leaks are
evident.
f.
It is advisable to use an electronic leak detector to check this system instead of an
open flame leak detector due to the possible presence of gasoline fumes in the engine
area.
g. If any leaks are found, purge the system of refrigerant, make the necessary repairs
and check the compressor oil.
h. Add oil, if required, (refer to Paragraph 13-21 and Table XIII-III)then repeat steps a
thru e.
i.
If no further leaks are found, the system may be evacuated and charged. Refer to
Paragraphs 13-13 and 13-14.
ACCESSORIES AND UTILITIES
Issued: 8/17/72
3G19