Installation Of Hot Air Bypass Valve; Removal Of Bleed Air Supply Overpressure Switch; Installation Of Bleed Air Supply Overpressure Switch - Piper Cheyenne IIIA Airplane Maintenance Manual

PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
A. Heating and Cooling (continued)
6. Installation of Hot Air Bypass Valve
(a) Secure bypass valve and new seals to duct flange using previously removed couplings.
Torque couplings to 35 ± 3.5 inch-pounds.
(b) Connect electrical connector to bypass valve.
(c) Engage cabin temperature circuit breaker.
7. Removal of Bleed Air Supply Overpressure Switch
(a) Gain access to overpressure switch. (Figure 401)
(b) Disconnect electrical connector from switch.
(c) Cut safety wire and unscrew switch from receptacle.
(d) Remove switch and O-ring.
8. Installation of Bleed Air Supply Overpressure Switch
(a) Install new switch and O-ring into receptacle.
NOTE: Ensure proper high temperature O-ring is used by referring to Parts Catalog.
(b) Secure switch with safety wire.
(c) Reconnect electrical connector switch.
9. Removal of Compressor Discharge Overtemperature Sensing Switch
(a) Gain access to overtemperature switch. (Figure 401)
NOTE: Note location of each wire to facilitate reinstallation.
(b) Disconnect electrical leads from switch.
(c) Loosen nut and unscrew switch from receptacle.
(d) Remove switch and O-ring.
10. Installation of Compressor Discharge Overtemperature Sensing Switch
(a) Install new switch and O-ring into receptacle.
NOTE: Ensure proper high temperature O-ring is used by referring to Parts Catalog.
(b) Screw switch into receptacle.
(c) Connect wires to switch.
EFFECTIVITY:
040-999
21-40-00
PAGE
5
21-40-00
Jan
10/90