1995 SUBARU LEGACY oil pressure

2. MEASUREMENT OF HYDRAULIC PRESSURE
CAUTION:
Be sure to complete all items aforementioned in
“STEERING CONDITION”[K101], prior to measuring
hydraulic pressure. Otherwise, pressure can not be
measured correctly.
Measure regular pressure at
idling with valve opened.
GOOD
NOT GOOD
Flattened pipes or hosesReplace bad parts.
NOT GOOD
Leakage of fluid lineReplace.
NOT GOOD
Obstacle in fluid lineReplace fluid or component of
fluid line.
Measure relief pressure at
idling with valve closed.
GOOD
NOT GOOD
Poor work of relief valveReplace oil pump.
NOT GOOD
Fluid leakage inside oil pump
NOT GOOD
Excessive wear of vane pump
mechanism
Measure working pressure of
control valve at idling with
valve opened, turning steering
wheel from stop to stop.NOT GOOD
Poor work of control valveReplace valve assembly or
pinion and valve assembly.
CAUTION:

Do not leave the valve of pressure gauge closed or
hold the steering wheel at stop end for 5 seconds or
more in any case, as the oil pump may be damaged
due to long keep of these conditions.

Put cotton cloth waste at a place where fluid drops
before pressure gauge is installed. Wipe off split fluid
thoroughly after the measurement.
NOTE:
Keep engine idling during the measurement.


85
4-3DIAGNOSTICS
1. Power Steering

9. BREAKAGE OF HOSES
Pressure hose burstExcessive holding time of relief
statusInstruct customers.
Malfunction of relief valveReplace oil pump.
Poor cold characteristic of fluidReplace fluid.
Forced out return hosePoor connectionCorrect.
Poor holding of clipRetighten.
Poor cold characteristic of fluidReplace fluid.
Fluid bleeding out of hose slightlyWrong layout, tensionedReplace hose.
Excessive play of engine due to
deterioration of engine mounting
rubberReplace defective parts.
Improper stop position of pitching
stopperReplace defective parts.
*11
Crack on hose
Excessive holding time of relief
statusReplace.
Instruct customer.
Excessive tightening torque for
return hose clipReplace.
Power steering fluid, brake fluid,
engine oil, electrolyte adhere on
the hose surfaceReplace.
Pay attention on service work.
Too many times use in extremely
cold weatherReplace.
Instruct customers.
*11 Although surface layer materials of rubber hoses have excellent weathering resistance, heat resistance and resistance for
low temperature brittleness, they are likely to be damaged chemically by brake fluid, battery electrolyte, engine oil and
automatic transmission fluid and their service lives are to be very shortened. It is very important to keep the hoses free
from before mentioned fluids and to wipe out immediately when the hoses are adhered with the fluids.
Since resistances for heat or low temperature brittleness are gradually declining according to time accumulation of hot or
cold conditions for the hoses and their service lives are shortening accordingly, it is necessary to perform careful inspec-
tion frequently when the vehicle is used in hot weather areas, cold weather area and/or a driving condition in which many
steering operations are required in short time. Particularly continuous work of relief valve over 5 seconds causes to reduce
service lives of the hoses, the oil pump, the fluid, etc. due to over heat.
So, avoid to keep this kind of condition when servicing as well as driving.
100
4-3DIAGNOSTICS
1. Power Steering

G4M0440
13. Proportioning Valve
G4M0668
G4M0915
A: INSPECTION
1) Install the oil pressure gauges to measure the master
cylinder fluid pressure (front wheel brake fluid pressure)
and rear wheel cylinder fluid pressure.
2) Bleed air from the oil pressure gauges.
3) Check the master cylinder fluid pressure and rear wheel
cylinder fluid pressure.
The standard values are shown in Figure.
4) For the oil pressure in case of split point, refer to A:
SPECIFICATIONS [S0A0].
B: REMOVAL
1) Remove brake pipe from proportioning valve at four
places.
2) Remove proportioning valve from its bracket.
CAUTION:
Do not disassemble or adjust the proportioning valve.
(The proportioning valve must be replaced as an
assembly.)
C: INSTALLATION
1) Install proportioning valve to bracket.
2) Connect brake pipes correctly to proportioning valve.
3) Bleed air, then check each joint of brake pipe for oil
leaks.
Tightening torque:
Proportioning valve to brake pipe flare nut:
15
+3
2N⋅m (1.5+0.3
0.2kg-m, 10.8+2.2
1.4ft-lb)
Proportioning valve to bracket:
18±5 N⋅m (1.8±0.5 kg-m, 13.0±3.6 ft-lb)
59
4-4SERVICE PROCEDURE
13. Proportioning Valve

3. REFRIGERANT
Do not put CFC-12 refrigerant into a HFC-134a air condi-
tioning system. Also, do not put HFC-134a refrigerant into
a CFC-12 air conditioning system. If the wrong refrigerant
is used, poor lubrication will result and the compressor
itself may be destroyed.
G4M0979
4. HANDLING OF REFRIGERANT
Because refrigerant boils at approx. 30°C (22°F) at sea
level, it is cold enough to give you severe frostbite. Always
wear goggles to protect your eyes and gloves to protect
your hands. Also, even under the pressures normally found
in CFC-12 containers, refrigerant will boil with the addition
of heat. This could raise the pressure inside the container
to a dangerous level.
Never expose a can of HFC-134a to direct sunlight, or to
temperatures over 40°C (104°F). One more thing to
remember about HFC-134a is that when it is exposed to an
open flame or to hot metal, it forms phosgene, a deadly
gas. Do not discharge HFC-134a into the atmosphere on
purpose. Always read and follow the precautions on the
HFC-134a bottle.
10
4-7SERVICE PROCEDURE
1. Safety Precautions

2. Basic Information
1) The combination of moisture and refrigerant forms acid,
therefore, moisture should not be allowed to enter the
refrigerant.
2) Refrigerant oil readily absorbs moisture, therefore, keep
refrigerant oil containers tightly capped.
3) The process of evacuating the system is performed to
remove small amounts of moisture. This is accomplished
by lowering the pressure inside the system, which allows
the moisture to boil off, in much the same way that a pot
of water will boil away to nothing given enough time. The
evacuation process does not suck the moisture out of the
system.
4) A minimum level of vacuum must be reached to satis-
factorily evacuate the system. This minimum level of
vacuum depends on the temperature inside the system.
The chart below shows the level of vacuum required to boil
water at various temperatures.
Additionally, the vacuum level shown on a gauge will read
approx. 4 kPa (25 mmHg, 1 inHg) less for each 304.8 m
(1,000 ft) above sea level, due to the decrease in atmo-
spheric pressure at altitude.
Vacuum level required to boil water (at sea level)
Temperature°C(°F) Vacuum kPa (mmHg, inHg)
1.7 (35) 100.9 (757, 29.8)
7.2 (45) 100.6 (754, 29.7)
12.8 (55) 99.9 (749, 29.5)
18.3 (65) 99.2 (744, 29.3)
23.9 (75) 98.5 (739, 29.1)
29.4 (85) 97.2 (729, 28.7)
35 (95) 95.8 (719, 28.3)
11
4-7SERVICE PROCEDURE
2. Basic Information

8. Leak Testing
The following points should be kept in mind when conduct-
ing a refrigerant leak test.
1) The A/C system to be tested must have an adequate
refrigerant charge to begin with.
2) The area where the leak test is conducted must be free
of wind and drafts, with still air being the ideal condition.
3) The atmosphere where the leak test is conducted must
be free of refrigerant contamination.
4) Operate the A/C system for approx. 10 minutes, then
turn the engine off an begin the leak test.
5) Refrigerant gas is heavier than air, therefore always
hold the probe below the connection being tested.
6) When checking for a leak along a length of hose or
tube, the leak detector probe must be moved slowly,
approx. 25 mm (1 in) per second making sure probe does
not come in contact with the component being tested.
7) When checking for a leak at a certain point, the leak
detector probe must be held at that point for at least 5
seconds.
G4M0609
1. CHECK THE SYSTEM PRESSURE
With gauges connected to the A/C system, operate the A/C
and confirm that the high side pressure is above 690 kPa
(7.03 kg/cm
2, 100 psi). If not, evacuate and charge the
system before leak checking (refer to evacuation and
charging sections).
2. CLEAN CONNECTIONS BEFORE TESTING
Before testing, use a clean shop towel to wipe off refriger-
ant oil, dirt, or foreign material from all of the connections
and components to be tested.
NOTE:
Since refrigerant oil absorbs refrigerant, excess oil on or
near a connection may falsely signal a leak.
B4M0089
3. CALIBRATE LEAK DETECTOR
Refer to the manufacturer’s instructions for the particular
type of detector used and calibrate the instrument.
CAUTION:
Always make sure that the probe tip filter is clean and
free of contamination.
23
4-7SERVICE PROCEDURE
8. Leak Testing

G4M0612
4. LEAK TEST — HIGH-PRESSURE SIDE
Operate the A/C system for approx. 10 minutes, then turn
the engine off and begin the leak test.
1) Begin at the connection of the high-pressure tube to the
evaporator, and work your way along the high- pressure
side of the system to the compressor. There are three
places to check on each tube connection.
2) Check the area.
(1) Check the area where the fitting joins the tube.
G4M0613
(2) Check the area where the two parts of the fitting
join each other.
G4M0614
(3) Check the area where the nut joins the tube.
3) Check the area of the sight glass and pressure switch
(dual switch), and also check the seams of the receiver
drier.
4) Check the connections of the tubes to the condenser,
and also check any welded joints on the condenser.
CAUTION:
An oily area on the fins of the condenser may indicate
a leak.
5) Check the area where the hoses attach to the compres-
sor.
6) Check around the machined portions of the compressor
(where the compressor sections join each other).
7) If equipped, check the thermal limiter on the compres-
sor housing.
8) Check the compressor shaft seal by probing near the
center of the compressor clutch pulley.
NOTE:
Some shaft seals have a very slight amount of normal
leakage [approximately 28 g (1.0 oz) per year].
24
4-7SERVICE PROCEDURE
8. Leak Testing

9. Lubrication
1. SYSTEM OIL STABILIZATION
Prior to opening the refrigerant system for repairs (except
compressor seizure) the system must be stabilized for cor-
rect oil replenishment.
Follow these procedures:
1) Engine speed set to 1,500 rpm
2) A/C“ON”
3) Air source to recirculate
4) Blower in 4th or high speed position
Make sure the air entering the evaporator is above
26.7°C (80°F).
The discharge (high) side pressure must be above
588 kPa (6 kg/cm
2, 85 psi).
5) Operate the A/C for 10 minutes.
2. SYSTEM DISCHARGE
Slowly, discharge the system starting with the high- pres-
sure side until the pressure drops below 345 kPa (3.52
kg/cm
2, 50 psi), then open the low-pressure side.
3. OIL REPLACEMENT (LHD MODEL)
After stabilization and discharge, replace the component,
adding the appropriate amount of oil (ZXL100PG) to the
new component before installation.
Evaporator 114 m
(3.9 US fl oz, 4.0 Imp fl oz)
Receiver drier 5 m
(0.2 US fl oz, 0.2 Imp fl oz)
Condenser 2 m
(0.07 US fl oz, 0.07 Imp fl oz)
Hose 1 m
(0.03 US fl oz, 0.04 Imp fl oz)
If the compressor is replaced (after stabilization):
1) Drain and measure the oil from the original compressor.
2) Drain the oil from the replacement compressor and refill
with the same amount that was drained from the original
[20 m
(0.7 US fl oz, 0.7 Imp fl oz) minimum]. Always use
ZXL100PG for the replacement oil.
27
4-7SERVICE PROCEDURE
9. Lubrication