1999 SUBARU LEGACY cooling

Condition Probable cause Corrective action
G4M0676
G4M0677
Insufficient cooling;
Sweated suction line.
No cooling;
Sweating or frosted suc-
tion line.Expansion valve allows
too much refrigerant
through evaporator.
Faulty seal of O-ring in
expansion valve.Check valve for opera-
tion. If suction side does
not show a pressure
decrease, replace valve.
(1) Discharge system.
(2) Remove expansion
valve and replace
O-ring.
(3) Evacuate and
replace system.
AIR IN SYSTEM
G4M0678
Insufficient cooling Air mixed with refriger-
ant in system.(1) Discharge system.
(2) Replace receiver
drier.
(3) Evacuate and
charge system.
MOISTURE IN SYSTEM
G4M0679
After operation for a
while, pressure on suc-
tion side may show
vacuum pressure read-
ing. During this
condition, discharge air
will be warm. As warn-
ing of this, reading
shows 39 kPa (0.4
kg/cm
2, 6 psi) vibration.Drier is saturated with
moisture. Moisture has
frozen at expansion
valve. Refrigerant flow
is restricted.(1) Discharge system.
(2) Replace receiver
drier (twice if neces-
sary).
(3) Evacuate system
completely (repeat
30-minute evacuating
three times.).
(4) Recharge system.
36
4-7[K200]DIAGNOSTICS
2. Performance Test Diagnosis

Condition Probable cause Corrective action
FAULTY CONDENSER
G4M0680
No cooling action;
Engine may overheat.
Suction line is very hot.Condenser is often
found not functioning
well.ICheck condenser
cooling fan.
ICheck condenser for
dirt accumulation.
ICheck engine cooling
system for overheat.
ICheck for refrigerant
overcharge.
If pressure remains
high in spite of all
above actions taken,
remove and inspect
the condenser for
possible oil clogging.
HIGH-PRESSURE LINE BLOCKED
G4M0681
Insufficient cooling;
Frosted high-pressure
liquid line.Drier is clogged, or
restriction in high- pres-
sure line.(1) Discharge system.
(2) Remove receiver
drier or strainer and
replace it.
(3) Evacuate and
charge system.
FAULTY COMPRESSOR
G4M0682
Insufficient cooling Internal problem is in
compressor, or dam-
aged gasket and valve.(1) Discharge system.
(2) Remove and check
compressor.
(3) Repair or replace
compressor.
(4) Check oil level.
(5) Replace receiver
drier.
(6) Evacuate and
charge system.
37
[K200]4-7DIAGNOSTICS
2. Performance Test Diagnosis

(3) Remove stator coil from diode plate.
B6M0481
8) Remove bolts which secure IC regulator, diode
and brush holder.
CAUTION:
Do not apply a shock or load to IC regulator
cooling fins.
B6M0482
C: INSPECTION
1. ROTOR
1) Slip ring surface
Inspect slip rings for contamination or any rough-
ness of the sliding surface.
Clean or polish with #500 to #600 emery paper if
defective.
B6M0769A
2) Slip ring outside diameter
Measure slip ring outside diameter. If slip ring is
worn, replace rotor.
Slip ring outside diameter:
Standard
27 mm (1.06 in)
Limit
26 mm (1.02 in)
B6M0483A
3) Continuity test
Check continuity between slip rings. If continuity
does not exist, replace rotor.
B6M0484A
4) Insulation test
Check continuity between slip ring and rotor core
or shaft. If continuity exists, replace rotor.
B6M0485A
17
[W2C1]6-1SERVICE PROCEDURE
2. Generator