MCi Crusader II 1989 Maintenance Manual page 491

Date
1-1-89
Page
16-21
MC-9 ·MAINTENANCE MANUAL
A/C SYSTEM TROUBLESHOOTING
TROUBLE
LOW SUCTION PRESSURE AND_ FROSTING
AT DRYER OUTLET
Clogged filter-dryer element.
LOW OIL LEVEL
EXCESSIVELY COLD SUCTION LINE
Loss of contact between the expansion valve
bulb and the suction line or sticking otthe expan-
sion valve.
EXCESSIVELY COLD SUCTION LINE AND
NOISY COMPRESSOR
COM.PRESSOR SQUEAKS OR SQUEALS
WHEN RUNNING
NOISY OR KNOCKING COMPRESSOR
;OMPRESSOR VIBRATES
EXCESSIVELY HOT CONDENSER AND HIGH
DISCHARGE PRESSURE
Air or non-condensable gas in system.
LOW REFRIGERANT LEVEL
SUCTION PRESSURE RISES FASTER THAN
5 POUNDS PER MINUTE AFTER SHUTDOWN
INSUFFICIENT COOLING
INSUFFICIENT AIR FLOW
Dirty or iced evaporator.
Dirty air filter.
Blowers inactive.
Clogged ducts.
FLOW OF REFRIGERANT THROUGH
EXPANSION VALVE
Dehydrator strainer is clogged.
Remote bulb has lost charge.
Expansion valve is detective.
EXPANSION VAL VE HISSES
BUBBLES IN MOISTURE ANO LIQUID
INDICATOR
Sas in liquid line.
LOSS OF CAPACITY
Clogged dehydrator.
Obstructed or defective expansion valve.
REMEDY
Clean filter element.
Check for oil leaks and for a leaking oil seal.
Do not attempt to check oil level unless system has been stabil-
ized at least 20 minutes.
Check for foreign matter and clean, repair or replace the valve.
1. Check superheat adjui;tment.
2. Check remote bulb contact.
3. Check expansion valve for sticking.
1. Check oil level.
2. Replace oil seal.
1. Check for broken internal parts.
2. Overhaul it required.
Check and tighten compressor mounting bolts.
Purge system.
Check for refrigerant leaks and add refrigerant if required.
Check compressor valve for breakage or damage.
1. Check for refrigerant leaks.
2. Check condition of filter screens and motors.
1. Check and clean evaporator, filters, ducts.
2. Recycle system.
1. Clean strainer.
2. Replace remote bulb and/or expansion valve.
Add refrigerant.
Check and clean as required.