AirComm Corporation Beechcraft Bonanza Maintenance Manual

							  Products, L.P.                                    CR-36-10 System Service Manual 
 
4. COMPRESSOR TROUBLESHOOTING 
  
A. General 
 
The following procedures are used for troubleshooting the compressor. 
 
B. Tools and Equipment 
  
Designation 
 
Ref. No. 
 
Qty 
 
Remarks 
 
Service Pressure Gauge 
 
Comm. Avail. 
 
1 
 
None 
 
14vdc or 28vdc Source (depends on 
model) 
 
 
 
A/R 
 
None 
 
C. Compressor Troubleshooting Procedures 
 
With the air conditioning system operating, check for any of the following conditions. 
 
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. 
 
 
Repair leak or replace 
compressor. 
 
 
(a) Inspect/replace 
exhaust duct. 
(b) Discharge 
refrigerant until only 
occasional bubbles are 
present in sight glass. 
 
 
 
Replace compressor. 
 
 
 
 
 
Replace compressor.
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							  Products, L.P.                         CR-36-10 System Service Manual 
 
CHECKS 
 
1. GENERAL 
 
The following procedures are used to perform typical maintenance checks for air 
conditioning system refrigerant leaks, refrigerant charge and compressor oil level. 
 
CAUTION: Do not operate air conditioning system with condenser air outlet blocked. 
 
A. Tools and Equipment 
  
Designation 
 
Ref. No. 
 
Qty 
 
Remarks 
 
Service Pressure Gage 
 
Comm. Avail. 
 
1 
 
None 
 
Electronic Leak Detector 
 
Comm. Avail. 
 
A/R 
 
Type H-10G 
 
Polyolester Oil 
 
Comm. Avail. 
 
A/R 
 
Viscosity (ISO) 68 
 
2. REFRIGERANT LEVEL CHECK 
 
A. Select air conditioning system switch to AIR COND position. 
B. Set the cabin temperature knob to the MAX position. 
C. Set the fan speed knob to the HI position. 
D. Run system for five (5) minutes minimum. 
E. Check that the receiver/drier inlet and outlet fitting temperatures are the same.  If 
the outlet is colder, the receiver/drier screen is clogged.  Clean screen and re-
start refrigerant level check. 
F. Check sight glass for sufficient amount of bubbles.   
NOTE: The refrigerant bubbles are more difficult to see at ambient temperatures 
below 65/F.  Always re-check refrigerant level when ambient temperature 
is above 65/F for proper level. 
Page 18  
						

							  Products, L.P.                         CR-36-10 System Service Manual 
 
3. REFRIGERANT SYSTEM LEAKAGE CHECK 
 
A. The system leakage check is to be performed in an area with an ambient 
temperature of 65/F or above. 
B. Install service pressure gage to low and high pressure R134a service valves. 
C. Check for system pressure of approximately 64 psig or above.  The low pressure 
gage may be used to check system pressure.  If system pressure is below 64 
psig, a small amount of refrigerant R134a may be added to obtain the required 
pressure. 
D. On systems that have not been operated for 2 weeks or longer, operate the 
system for a minimum of 15 minutes.  This will lubricate the compressor shaft 
seal and ensure a more accurate leakage check of the shaft seal. 
E. With the system off, and using a type H-10G electronic leak detector or 
equivalent, check all connections, compressor shaft seal, and fabricated 
components for leakage.  No leakage is acceptable. 
 
4. COMPRESSOR OIL LEVEL CHECK 
 
NOTE: It is not necessary to check the compressor oil level during routine 
maintenance.  It only needs to be checked when a system component is 
replaced or when incorrect oil level is suspected.  Only polyolester oil 
viscosity grade ISO 68 should be used. 
 
1. Operate air conditioning system for 10 minutes.  This will collect as much 
oil as possible in the compressor. 
2. Discharge air conditioning system in accordance with Refrigerant 
Servicing instructions. 
3. Remove either discharge or suction port hose fitting. 
4. Remove oil drain plug and allow all oil to drain. 
5. Clean oil drain area and install drain plug.  Torque to 6 - 9 ft-lbs. 
6. Add 5 ounces of oil to compressor. 
7. Install hose fitting. 
8. Charge air conditioning system in accordance with Refrigerant Servicing 
instructions. 
Page 19  
						

							  Products, L.P.                         CR-36-10 System Service Manual 
 
 
5. COMPRESSOR DRIVE BELT ADJUSTMENT 
 
  1.  Adjust Idler pulley outboard left hand side to obtain moderate belt tension. 
 
  2.  Rotate propeller through 2 revolutions. 
 
  3.  Tension belt to deflect 0.18 inch with a 5 lb. Force applied at the mid-span  
   location  between the drive pulley and compressor pulley. 
 
  4.  Rotate propeller 2 revolutions, retention as required to obtain proper  
   deflection. 
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