1996 SUBARU LEGACY air condition

Whine or growl (continuous or
intermittent)
While engine is running with/
without steering turned.Loosened installation of oil pump,
oil pump bracketRetighten.
*8
Abnormal inside of oil pump, hoseReplace oil pump, hose, if the
noise can be heard when running
as well as stand still.
Torque converter growl
air conditioner compression growlRemove power steering pulley
belt and confirm.
Creaking noise (intermittent)
While engine is running with
steering turned.Abnormal inside of gearboxReplace bad parts of gearbox.
Abnormal bearing for steering
shaftApply grease or replace.
*9
Generates when turning steering
wheel with brake (service or park-
ing) applied.If the noise goes off when brake
is released, it is normal.
*10
Vibration
While engine is running with/
without steering turned.
Too low engine speed at startAdjust and instruct customers.
Vane pump aerationFix wrong part.
Vent air.
Damaged valve in oil pump, gear-
boxReplace oil pump, bad parts of
gearbox.
Looseness of play of steering,
suspension partsRetighten.
*8 Oil pump makes whine or growl noise slightly due to its mechanism. Even if the noise can be heard when steering wheel
is turned at stand still there is no abnormal function in the system provided that the noise eliminates when the vehicle is
running.
*9 When stopping with service brake and/or parking brake applied, power steering can be operated easily due to its light
steering effort. If doing so, the disk rotates slightly and makes creaking noise. The noise is generated by creaking between
the disk and pads. If the noise goes off when the brake is released, there is no abnormal function in the system.
*10 There may be a little vibration around the steering devices when turning steering wheel at standstill, even though the com-
ponent parts are properly adjusted and have no defects.
Hydraulic systems are likely to generate this kind of vibration as well as working noise and fluid noise because of com-
bined conditions, i.e., road surface and tire surface, engine speed and turning speed of steering wheel, fluid temperature
and braking condition.
This phenomena does not indicate there is some abnormal function in the system.
The vibration can be known when steering wheel is turned repeatedly at various speeds from slow to rapid step by step
with parking brake applied on concrete road and in“D”range for automatic transmission vehicle.
96
4-3DIAGNOSTICS
1. Power Steering

G4M0744
2. AIR TIGHTNESS CHECK
Start engine, and run it for 1 to 2 minutes, then turn it off.
Depress brake pedal several times applying the same
pedal force as that used in ordinary braking operations.
The pedal stroke should be greatest on the 1st depression,
and it should become smaller with each successive
depression. If no change occurs in the pedal height while
in a depressed state, brake booster is faulty.
NOTE:

In the event of defective operation, inspect the condition
of the check valve and vacuum hose.

Replace them if faulty and conduct the test again.

If no improvement is observed, check precisely with
gauges.
G4M0914
3. OPERATION CHECK
1) With engine off, depress brake pedal several times
applying the same pedal force and make sure that the
pedal height does not vary with each depression of the
pedal.
2) With brake pedal depressed, start engine.
3) As engine starts, brake pedal should move slightly
toward the floor. If no change occurs in the pedal height,
brake booster is faulty.
NOTE:
If faulty, check precisely with gauges.
4. LOADED AIR TIGHTNESS CHECK
Depress brake pedal while engine is running, and turn off
engine while the pedal is still depressed. Keep the pedal
depressed for 30 seconds; if no change occurs in the pedal
height, brake booster is functioning normally; if the pedal
height increases, it is faulty.
NOTE:
If faulty, check precisely with gauges.
52
4-4SERVICE PROCEDURE
6. Brake Booster

12. Brake Fluid Replacement
NOTE:
To always maintain the brake fluid characteristics, replace
the brake fluid according to maintenance schedule or ear-
lier than that when used in severe condition.
A: REPLACEMENT
CAUTION:

The FMVSS No. 116, fresh DOT3 or 4 brake fluid
must be used.

Cover bleeder with waste cloth, when loosening it,
to prevent brake fluid from being splashed over sur-
rounding parts.

Avoid mixing different brands of brake fluid to pre-
vent degrading the quality of the fluid.

Be careful not to allow dirt or dust to get into the
reservoir tank.
NOTE:

During bleeding operation, keep the brake reserve tank
filled with brake fluid to eliminate entry of air.

Brake pedal operating must be very slow.

For convenience and safety, it is advisable to have two
man working.

The amount of brake fluid required is approximately 500
m
(16.9 US fl oz, 17.6 Imp fl oz) for total brake system.
1) Either jack-up vehicle and place a safety stand under it,
or lift-up vehicle.
2) Remove both front and rear wheels.
3) Draw out the brake fluid from reserve tank with syringe.
4) Refill reservoir tank with recommended brake fluid.
Recommended brake fluid:
FMVSS No. 116, fresh DOT3 or 4 brake fluid
64
4-4SERVICE PROCEDURE
12. Brake Fluid Replacement

G4M0436
16) Check the pedal stroke.
While the engine is idling, depress the brake pedal with a
490 N (50 kg, 110 lb) load and measure the distance
between the brake pedal and steering wheel. With the
brake pedal released, measure the distance between the
pedal and steering wheel again. The difference between
the two measurements must be less than specified.
Specified pedal stroke:
With TCS
95 mm (3.74 in)
When depressing brake pedal with a 490 N (50 kg,
110 lb) load.
If the distance is more than specifications, there is a
possibility that air is in the brake line. Bleed air from the
brake line.
17) Turn ignition switch OFF.
18) Disconnect select monitor or diagnosis terminal.
19) Add brake fluid to the required level (MAX. level) of
reserve tank.
20) As a final step, test run the vehicle at low speed and
apply brakes relatively hard 2 to 3 times to ensure that
brakes provide normal braking action on all four wheels
without dragging and uneven braking.
2. CONDITIONS FOR AIR BLEEDING CONTROL
Stop light
switchTCS OFF
switchPump
motorTCS
valveFRO
RLOFLO
RROTCS
operating
indicator
lightABS
warning
lightTCS
warning
light
Air
bleeding
control is
operating.OFF ON ON Close Close Close ON ON ON
ON ON OFF Open Open Close ON ON OFF
ON ON OFF Open Close Open ON OFF ON
ON or OFF OFF OFF Open Close Close ON OFF OFF
Stops tem-
porarily.*——OFF Open Close Close OFF OFF OFF
Prohibited.——OFF Open Close Close OFF ON ON
*: When brake fluid level switch detects brake fluid in LOW level, control operation stops temporarily. After refilling brake fluid, operation
re-starts.
89
4-4SERVICE PROCEDURE
19. Air Bleeding (With TCS model)

3. CONDITIONS FOR COMPLETION OF AIR
BLEEDING CONTROL
When any of the following conditions occurs, ABS and TCS
warning lights illuminate. Air bleeding control stops, while
the ABS and TCS function will then stop. The brake sys-
tem functions as a conventional brake system.
1) When the speed of at least one wheel reaches 10 km/h
(6 MPH).
2) When terminal No. 4 is separated from diagnosis termi-
nal. (When select monitor is not used.)
3) When pump motor remains ON for two minutes.
4) When TCS valve remains open for two minutes.
5) When outlet valve remains closed for two minutes.
6) When malfunction is detected.
NOTE:
When a malfunction is detected the air bleeding operation
stops and the trouble codes are stored in memory.
B4M0082C
C: AIR BLEEDING CONTROL WITH
DIAGNOSIS CONNECTOR
1) Connect diagnosis terminals to terminal No. 4 of the
diagnosis connector beside driver’s seat heater unit.
B4M0621A
2) Start the engine while pushing TCS OFF switch.
NOTE:
Keep the TCS OFF switch depressed even after the engine
has started.
3) After ABS and TCS warning lights go out, depress
brake pedal within 0.5 seconds.
4) After ensuring TCS ON indicator illuminates, release
TCS OFF switch and brake pedal.
5) Air bleeding control operation starts.
90
4-4SERVICE PROCEDURE
19. Air Bleeding (With TCS model)

D: ABS SEQUENCE CONTROL
1) Under the ABS sequence control, after the hydraulic
unit solenoid valve is driven, the operation of the hydraulic
unit can be checked by means of the brake tester or pres-
sure gauge.
2) ABS sequence control can be started by diagnosis con-
nector or select monitor.
B4M0082C
1. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR
1) Connect diagnosis terminals to terminal No. 4 of the
diagnosis connector beside driver’s seat heater unit.
2) Ignition switch is turned to ON.
3) Make sure only the start code (code 11) is shown in
normal condition.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
4) Set the speed of all wheels at 10 km/h (6 MPH) or less.
5) Turn ignition switch OFF.
6) Within 0.5 seconds after the ABS and TCS warning
lights go out, depress the brake pedal and hold it immedi-
ately after engine starts.
NOTE:

When the ignition switch is set to on, the brake pedal
must not be depressed.

Engine must operate.

If brake pedal is not depressed within 0.5 seconds after
ABS and TCS warning lights go out, the trouble code mode
comes on.
7) After completion of ABS sequence control, turn ignition
switch OFF.
2. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH SELECT MONITOR
1) Connect select monitor to data link connector beside
driver’s seat heater unit.
2) Engine starts.
3) Put select monitor to TCS mode.
4) put select monitor to FBI mode. Make sure code 11 is
indicated.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
97
4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

F: TCS SEQUENCE CONTROL
1) Under the TCS sequence control, after the hydraulic
unit solenoid valve is driven, the operation of the hydraulic
unit can be checked by means of the brake tester or pres-
sure gauge.
2) TCS sequence control can be started by diagnosis con-
nector or select monitor.
B4M0082C
1. OPERATIONAL GUIDELINES OF THE TCS
SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR
1) Connect diagnosis terminals to terminal No. 4 of the
diagnosis connector beside driver seat heater unit.
2) Ignition switch is turned to ON.
3) Make sure only the start code (code 11) is shown in
normal condition.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
4) Set the speed of all wheels at 10 km/h (6 MPH) or less.
5) Turn ignition switch OFF.
6) Start engine, and within 0.5 seconds after the ABS
warning light and TCS warning light go out, press TCS OFF
switch. Within 1.0 second thereafter, release and press the
switch again. Then, keep the switch pressed.
NOTE:

When the TCS sequence control is set to on, the brake
pedal must not be depressed.

Engine must operate.

When TCS OFF switch is not depressed within 0.5 sec-
onds after ABS and TCS warning lights turn off, the trouble
code mode comes on.
7) After completion of TCS sequence control, turn ignition
switch OFF.
103
4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

B: INSPECTION
1) Check connected and fixed condition of connector.
2) Check valve relay and motor relay for discontinuity or
short circuits.
Condition Terminal number Standard Diagram Terminal location
Valve relayTurning off
electricity.85—86 103±10Ω
G4M0456G4M0457
30—87a less than 0.5Ω
30—87 more than 1 MΩ
Turning on
electricity between
85 and 86.
(DC 12 V)30—87a more than 1 MΩ
30—87 less than 0.5Ω
Motor relayTurning off
electricity.85—86 80±8Ω
G4M0458G4M0459
30—87 more than 1 MΩ
Turning on
electricity between
85 and 86.
(DC 12 V)30—87 less than 0.5Ω
C: CHECKING THE HYDRAULIC UNIT ABS
OPERATION
1. CHECKING THE HYDRAULIC UNIT ABS
OPERATION BY PRESSURE GAUGE
1) Lift-up vehicle and remove wheels.
2) Disconnect the air bleeder screws from the FL and FR
caliper bodies.
B4M0633A
3) Connect two pressure gauges to the FL and FR caliper
bodies.
CAUTION:

Pressure gauges used exclusively for brake fluid
must be used.

Do not employ pressure gauge previously used for
transmission since the piston seal is expanded which
may lead to malfunction of the brake.
NOTE:
Wrap sealing tape around the pressure gauge.
111
4-4SERVICE PROCEDURE
22. Hydraulic Unit for ABS System (ABS 5.3 Type)