Partial Charge Of Air Conditioning System - Piper PA-44-180 SEMINOLE Maintenance Manual

10. Shut off air conditioning system and airplane engine. Then, remove the charging lines from the Schrader
valves with care due to the refrigerant remaining in the hose.
A shop cloth should be used to divert escaping refrigerant when disconnecting the
charging hose from the Schrader valve. Recap the valve.
PARTIAL CHARGE OF SYSTEM.
To "top off" the air conditioning system with refrigerant, proceed as follows:
1. Remove the access panel at the rear of the cabin.
2. Connect a charging hose to a refrigerant cylinder and also to the Schrader valve fitting on the suction
line. (Refer to Figure 21-30.)
3. Purge the charging hose by allowing a small amount of refrigerant gas to escape at the Schrader valve
fitting.
4. Start the engine and operate at 1000 RPM and turn the air conditioner on maximum cool.
5. Remove the plastic plug from the sight glass in the top of the receiver-dehydrator.
6. With a low refrigerant charge in the system, bubbles will be seen passing thru the sight glass when the
system is operating.
7. Open the valve on the refrigerant cylinder.
8. Allow refrigerant to flow into the system until the bubbles disappear from the sight glass.
9. Close the refrigerant valve and check to see that the sight glass remains clear during the system
operation.
10. When the sight glass stays clear of bubbles, add an additional 1/4 pound of refrigerant to the system.
(Engine should be operating at 1000 RPM.)
This should be done with OAT at 70°F, or higher, with the air conditioner operating.
11. Shut off the air conditioner and engine. Remove the charging hose from the Schrader valve with care due
to refrigerant remaining in the line.
12. Replace access panels.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
— Note —
— Note —
1H10
2 1 - 5 2 - 1 0
Page 21-67
Revised: May 15, 1989