AirComm Corporation Cessna Citation 550 560 Maintenance Manual

							 Products, Inc. 
                                                           Maintenance Manual 
 
 
21-50-02 
May 15/95 Page1 
 PLUMBING 
 
DESCRIPTION AND OPERATION 
 
1. GENERAL 
 
The plumbing system consists of a flexible nylon lined refrigerant hose with 
permanent swaged on fittings.  All connections are tube O-ring type with sealant on 
the fitting mating surfaces to ensure leak free operation.  Hose, O-ring material, and 
sealant are specially designed to work with refrigerant R134a and polyol ester oils.  
Two service valves are located near the compressor/condenser assembly.   They 
are sized differently to avoid incorrect cross-connecting when gaining access to the 
plumbing for system recharging.  A receiver/drier is installed downstream of the 
condenser to remove moisture from the liquid refrigerant.   A binary pressure switch 
monitors the refrigerant gas pressure.  This switch will open at a condenser over 
pressure of 350 psi and under pressured conditions of 30 psi.  This will interrupt the 
power to the compressor control circuit and stop the compressor. 
 
This section of the maintenance manual discusses checks and maintenance 
practices used for the plumbing portion of the air conditioning system.  An Illustrated 
Parts List is included in Figure 1.   
						

							 Products, Inc. 
                                                           Maintenance Manual 
 
 
 
21-50-02 
May 15/95
 Page 201 
MAINTENANCE PRACTICES 
 
1. GENERAL 
 
The following procedures are used to perform typical maintenance on the air 
conditioning system plumbing. 
 
2.  TOOLS AND EQUIPMENT 
 
 
Designation  
Ref. No.  
Qty  
Remarks 
 
 
R134a Compatible Hose Swaging 
Kit  
Available from 
Keith Products  
1  
None 
 
Sharp Knife  
Comm. Avail.  
1  
None 
 
Impact Wrench  
Comm. Avail.  
1  
None 
 
Polyol Ester Oil  
Comm. Avail.  
A/R  
Viscosity Grade 68 
 
Sealant  
ES49000-1  
A/R  
None 
 
3.  PLUMBING MAINTENANCE PROCEDURES (REF. IPL Fig. 1) 
 
A.  Hose or Fitting Replacement 
 
NOTE:  If it is found that a hose or fitting has a leak, it will be necessary to replace 
the entire hose assembly.  Follow the Hose Swaging Instruction below: 
 
1.  Hose should only be cut with a sharp knife.  (Note:  Use of serrated blades 
or saws to cut hose will leave particles that can contaminate system.) 
2.  Insert the proper size die in the swaging tool. 
3.  Insert fitting in swaging tool so that it is centered in the die and hand tighten. 
4.  Insert hose in fitting until it bottoms (Note:  Indicating hole is in base of 
fitting). 
5.  Using impact wrench, tighten nut until die housings contact.  (Note:  It is 
important to keep hose pushed into fitting while swaging). 
6.  Reverse impact and back off nut until housing contacts rubber stops. 
  
						

							 Products, Inc. 
                                                            Maintenance Manual 
 
 
21-50-02 
May 15/95
 Page 202 
 
B.  Connection to Components - O-Ring Replacement 
1.  Place the appropriate o-ring (REF. IPL Fig. 1) over the tube O end of the 
fitting.   
2.  Lubricate o-ring with polyol ester oil or sealant prior to assembly. 
3.  Apply sealant to all fitting mating surfaces prior to assembly. 
 
C. Receiver/Drier Replacement 
1.  Replace receiver/drier whenever the compressor is replaced or when the 
air conditioning system plumbing is left open to the atmosphere. 
 
  
						

							 Products, Inc. 
                                                            Maintenance Manual 
 
 
21-50-02 
May 15/95
 Page 601 
 
INSPECTION/CHECK 
 
1. GENERAL 
 
The following procedures are used for checking and inspecting the air conditioning 
system plumbing. 
 
2.  TOOLS AND EQUIPMENT 
 
 
Designation  
Ref. No.  
Qty  
Remarks 
 
 
Electronic R134a Refrigerant Leak 
Detector  
Comm. Avail.  
1  
None 
 
 
3.  PLUMBING CHECK PROCEDURES  (REF. IPL Fig. 1) 
 
A   Plumbing Installation Preventive Maintenance Check 
 
NOTE:  All O-rings should be lubricated with polyol ester oil or sealant applied 
to all fittings mating surfaces before assembly. 
 
1.  Check that all hoses are properly supported and do not chafe.  Check that 
all clamps remain secure and that the hose and fitting are well supported at 
connections with fixed units such as evaporator, condenser etc. to prevent 
fatigue cracking in tubing headers or fittings.   
 
B.  Plumbing System Refrigerant Leak Check 
1.  Connect service pressure gauge set to service ports, located near the 
compressor/condenser assembly. 
2.  Check that the gauges are reading the proper static pressure.  Both gauges 
should read approximately 55 psig @ standard temperature  (59°F) with a 
properly charged system when the system is not operating. 
3.  Using leak detector, check entire plumbing system including hose fittings 
and coil assemblies for leaks.  There shall be no leaks.  Repair or replace 
leaking component per the appropriate maintenance manual section and its 
IPL. 
   
						

							 Products, Inc. 
                                                         Maintenance Manual 
 
 
21-50-02 
May 15/95
 Page 1001 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 1.  Plumbing System  
						

							 Products, Inc. 
                                                           Maintenance Manual 
 
21-50-02 
May 15/95 Page 1002 
 
FIG. ITEM  
 PART 
 NUMBER  
 NOMENCLATURE  
 EFFECT  
 UNITS  
 PER  
 ASSY 
 
1 1 
2 
3 
4 
- 
- 
 
- 
- 
- 
- 
 
- 
- 
- 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35  
82-02-105-5,-6 
JBS5005-1 
JBS2030-3 
JBS2048-3 
88-00-431-1 
MS21919WDG
12 
MS20365-1032 
AN960-10 
NAS221-10 
MS21919WDG
9 
ES06022-1 
ES02162-2 
MS3367-7 
JBS10-64 
ES49011-1 
ES49011-3 
ES48149-1 
ES48149-3 
ES41061-1 
MS28775-114 
ES40150-3 
JBS6009-3 
AN6289-10D 
MS28775-211 
ES40149-3 
ES40158-3 
ES40151-3 
ES40151-1 
ES40158-1 
ES40149-1 
ES49016-1 
JBS6009-1 
ES40150-1 
ES41061-2  
Plumbing Installation  
Compressor/Condenser 
FWD Evaporator 
AFT Evaporator 
Drain Instl 
Clamp 
 
Nut 
Washer 
Screw 
Clamp 
 
Insulation Tape 
Insulation Tubing  
Cable Tie 
Placard 
O-ring 
O-ring 
Hose 
Hose 
Adapter Tee 
Bulkhead O-ring 
Fitting 
Bulkhead Fitting 
Nut 
Bulkhead O-ring 
Straight Fitting 
Service Valve 
90° Fitting 
90° Fitting 
Service Valve 
Straight Fitting 
BKHD Fitting Nut 
Bulkhead Fitting 
45° Fitting 
Tee  
 
 
 
 
  
 RF 
1 ref 
1 ref 
1 ref 
1 
20 
 
40 
9 
10 
20 
 
180 in 
288 in 
80 
4 
8 
8 
500 in 
500 in 
1 
1 
2 
1 
1 
1 
4 
1 
2 
1 
1 
6 
1 
1 
1 
1 
 
Air Conditioning System - Plumbing System 
IPL FIGURE 1 
 COMPRESSOR/CONDENSER ASSEMBLY
 
  
						

							 Products, Inc. 
                                                            Maintenance Manual 
 
21-50-03 
May 15-95 
Page 1 
 DESCRIPTION AND OPERATION 
 
1. GENERAL 
 
The compressor/condenser assembly is located either forward of the rear baggage 
door; or in the baggage compartment.  This unit consists of a drive motor, 
compressor, condenser fan assembly, condenser coil, and pressure switch.  The 
drive motor via a multi V flat belt, turns the compressor which compresses the 
refrigerant gas at which it will condense at ambient temperatures.  This gas is 
directed to the condenser where its heat is removed by air flow from the condenser 
fan.  The fan is attached to the long shaft of the drive motor.  This air is exhausted 
overboard via exhaust duct located either on the bottom of the aircraft or on the left 
side of the aircraft.  The condenser condenses the refrigerant gas to a liquid.  This 
liquid is collected by the receiver/drier where moisture is removed.  A binary 
pressure switch monitors the refrigerant gas pressure.  This switch will open at a 
condenser over pressure  of 350 psi and under pressure conditions of 30 psi.  This 
will interrupt the signal to the control board and stop the compressor/condenser unit. 
 
This section of the maintenance manual discusses troubleshooting and 
maintenance practices used for the compressor/condenser assembly portion of the 
air conditioning system.  An Illustrated Parts List is included in Figure 1.   
						

							 Products, Inc. 
                                                           Maintenance Manual 
 
 
21-50-03 
May 15/95 
Page 101 
 TROUBLESHOOTING 
 
1. GENERAL 
 
The following procedures are used for troubleshooting the comp/cond assembly. 
 
2.  TOOLS AND EQUIPMENT 
 
 
Designation  
Ref. No.  
Qty  
Remarks 
 
 
Service Pressure Gauge  
Comm. Avail.  
1  
None 
 
28vdc Source  
  
A/R  
None 
 
3.  COMP/COND TROUBLESHOOTING PROCEDURES (REF. IPL Fig. 1) 
 
With the air conditioning system operating, do any of the following conditions occur: 
 
NOTE:   Always attach a service gauge set to system prior to being trouble 
shooting to insure proper refrigerant charge is present. 
 
Trouble
       Probable Cause Correction 
1. Unusually high 
suction pressure 
with low discharge 
pressure. 
 
2. Unusually low 
suction and 
discharge pressure. 
 
3. High compressor 
discharge pressure. 
 
 
 
 
 
4. Rough running. 
 
 Internal problem with 
compressor body. 
 
 
 
System or compressor 
Leak. 
 
 
(a) Air exhaust duct 
collapsed or restricted. 
(b) Refrigerant 
overcharge. 
 
 
 
Internal compressor 
problem. 
 
Replace compressor. 
  
 
 
Repair leak or replace 
compressor. 
 
 
(a) Inspect/replace 
exhaust duct. 
(b) Discharge refrigerant 
until only occasional 
bubbles are present in 
sight glass. 
 
Replace compressor.  
						

							 Products, Inc. 
                                                           Maintenance Manual 
 
21-50-03 
May 15/95 
Page 102 
  Trouble
       Probable Cause   Correction 
5.  Low air flow across 
condenser coil. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Dirty condenser coil.  Clean condenser coil.  
						

							 Products, Inc. 
                                                            Maintenance Manual 
 
21-50-03 
May 15/95 
Page 201 
 MAINTENANCE PRACTICES 
 
1. GENERAL 
 
The following procedures are used to perform typical maintenance on the 
compressor/condenser assembly. 
 
2.  TOOLS AND EQUIPMENT 
 
 
Designation  
Ref. No.  
Qty  
Remarks 
 
 
Feeler Gage  
Comm. Avail.  
1  
None 
 
Oil Dipstick  
Make from metal 
wire.  
1  
See Fig. 201. 
 
Coil Cleaner  
Comm. Avail.  
A/R  
Non Acid Based 
 
Polyol Ester Oil  
Comm. Avail.  
A/R  
Viscosity Grade 68 
 
3. COMPRESSOR/CONDENSER MAINTENANCE PROCEDURES (REF. IPL Fig. 1) 
 
A.  Compressor Drive Belt Adjustment 
1.  Adjust belt for moderate tension and then rotate large pulley through 2 
revolutions. 
2.  Tension belt to deflect 0.16 inch with a 2 - 3 lb. force applied at midspan 
location. 
3.  Rotate belt 2 revolutions, retention as required. 
 
B.  Compressor Pulley Installation; Pulley - Bearing Carrier Air Gap Check 
 
NOTE: This procedure should be accomplished when installing the pulley on a 
new compressor to ensure proper pulley installation. 
 
1.  Add combination of shims from nut and shim kit (item 2) to ensure air gap 
between pulley and bearing carrier. Use .005 shim with stack. 
2.  Temporarily install pulley to shaft holding against shims. 
3.  Measure air gap between pulley and bearing carrier flange with feeler gauge, 
remove pulley. 
4.  Remove shim material .005 inch more than measured air gap. 
5.  Install pulley and woodruff key. 
6.  Install locknut from kit; torque to 25-30 ft lbs.