Subaru SVX 1992 Manual page 1039

AUTOMATIC AIR CONDITIONING SYSTEM (T1000I 4-7
10. Trouble Diagnosis for Abnormal Pressure
Whenever abnormal pressure in the high and/or low sides of the system is noted . Diagnosis must be conducted
by using a gauge manifold . The thick-line zone on the gauge scale (see illustrations) shown in the following table
refers to the standard (normal) pressure .
I Gauge indication I Refrigerant cycle I
Probable cause I Corrective action I
Both high- and low-pressure sides are too Pressure is reduced soon af-
high. ter water is splashed on con-
denser . No air bubbles ap-
pear in sight glass when
pressure is reduced .
Excessive refrigerant charge Reduce refrigerant until speci-
in refrigeration cycle I fied pressure is obtained .
Air suction by radiator or con- Insufficient condenser cooling
denser fan is insufficient. I performance
e Low-pressure pipe is not
cold .
e When compressor is
stopped, high-pressure
value quickly drops by ap-
proximately 196 kPa (2 kg/
cm 2, 28 psi) . It will then de-
crease gradually thereafter .
Engine tends to overheat
B4-713
Fig. 210
High-pressure side is too high and low-
pressure side is too low .
Fig . 211
B4-714
Area near low-pressure
pipe connection and service
valves are considerably
cold as compared with area
near expansion valve outlet
or evaporator .
" Parts are sometimes cov-
ered with frost.
Upper side of condenser and
high-pressure side are hot,
however, receiver drier is not
so hot .
1
1) Condenser fin is clogged .
2) Improper rotation of radia-
tor fan or condenser fan
Clean condenser.
Check and repair cooling
fan as necessary .
Poor heat exchange in con-
denser
(After compressor operation
stops, high pressure de-
creases too slowly.)
1
Air in refrigeration cycle
Engine cooling systems mal-
function .
Evacuate repeatedly and re-
charge system .
Excessive liquid refrigerant
on low-pressure side
" Excessive refrigerant dis-
charge flow
" Expansion valve is open a
little compared with the
specification.
1
1)Improper thermal valve in-
stallation
2)Improper expansion valve
adjustment
High-pressure hose or parts
located between compressor
and condenser are clogged or
crushed.
Check and repair each engine
cooling system .
Replace expansion valve .
" Check and repair or replace
malfunctioning parts.
Check compressor oil for
contamination .
105