air suspension SUBARU LEGACY 1996 Service Repair Manual

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

18. Brake Hose and Pipe
SUPPLEMENTAL RESTRAINT SYSTEM“AIRBAG”
Airbag system wiring harness is routed near the center
brake pipe.
CAUTION:

All Airbag system wiring harness and connectors
are colored yellow. Do not use electrical test equip-
ment on these circuit.

Be careful not to damage Airbag system wiring har-
ness when servicing the center brake pipe.
A: REMOVAL AND INSTALLATION
CAUTION:

When removing and installing the brake pipe, make
sure that it is not bent.

After installing the brake pipe and hose, bleed the
air.

After installing the brake hose, make sure that it
does not touch the tire or suspension assembly, etc.
1. MODELS WITHOUT ABS
G4M0472
1Union bolt

2Front brake hose RH

3Proportioning valve

4Front brake pipe

5Front adapter pipe (UPPER)

6Front adapter pipe (LOWER)

7Front brake hose LH
8Center brake pipe ASSY

9Connector bracket

10Two-way connector

11Rear brake pipe RH

12Rear brake hose drum

13Rear brake pipe ASSY

14Rear brake pipe LH
Tightening torque: N⋅m (kg-m, ft-lb)
T1: 13±3 (1.3±0.3, 9.4±2.2)
T2: 15
+3
2(1.5+0.3
0.2, 10.8+2.2
1.4)
T3: 18±3 (1.8±0.3, 13.0±2.2)
T4: 18±5 (1.8±0.5, 13.0±3.6)
82
4-4SERVICE PROCEDURE
18. Brake Hose and Pipe

2. Hill Holder
Trouble and possible cause Corrective action
1. Counterforce of clutch pedal is too strong.
(1) PHV cable is damaged or does not operate properly. Repair or replace.
(2) Lever of PHV is defective. Replace entire PHV assembly.
(3) Clutch system is anomalous. Refer to“Clutch and pedal cable system”.
2. Vehicle does not stop on uphill road of 3°or higher inclination.
(1) Front side of vehicle is lowered. Refer to“Suspension”.
(2) PHV cable is broken. Replace.
(3) Play of clutch is excessive. Adjust.
(4) PHV cable is elongated. Adjust.
(5) Sealing of PHV is poor. Replace entire PHV assembly.
3. Shock is felt when starting.
(1) Poor adjustment of starting performance: Adjust.
(2) When depressing the brake pedal strongly:(The stronger brake pedal depressing force, the later hill holder
releases.)
(3) When starting on flat road after stopping reverse movement: (Because hill holder is activated.)
4. Vehicle slips down when starting.
(1) PHV cable is elongated. Adjust.
(2) Clutch facing is worn out. Adjust or replace.
(3) Bracket (cable) or stay (PHV) is deformed. Repair or replace.
5. Vehicle cannot start after stoppage.
(1) Return spring is fatigued or broken. Replace.
(2) PHV lever won’t return. Replace entire PHV assembly.
(3) When intentionally depressing brake pedal strongly:[When the brake pedal is depressed by a force of 1,177 N (120
kg, 265 lb) or more.]
6. Abnormal sound is generated upon releasing brake pedal when stopping.
(1) Rotor and pad matched with each other due to inadequate
depressing force to brake pedal.(Abnormal sound is not generated when depressing brake pedal a
little stronger.)
7. Abnormal sound is generated when operating clutch pedal.
(1) Grease is inadequate for the hook of return spring and slid-
ing portion of PHV cable end.Apply grease.
(2) When releasing after maintaining high fluid pressure: (Flowing sound of fluid when releasing high fluid pressure.)
(3) Clutch system is anomalous. Refer to“Clutch and pedal cable system”.
CAUTION:

Description in parentheses is a characteristic of hill holder and does not indicate abnormality.
Depressing force required for clutch pedal equipped to hill holder specifications is 20 to 29 N (2 to 3 kg, 4 to 7 lb) larger than
the conventional specifications, which does not constitute abnormality.

When vehicle cannot travel (brake cannot be released) because return spring is broken, remove adjusting nut, disconnect
clutch and PHV, and then return PHV lever to release the brake. (Be sure to apply the parking brake before starting this opera-
tion.)

The hill holder may not be activated on a slope of an extremely small inclination.
126
4-4DIAGNOSTICS
2. Hill Holder

e. Malfunction indicator light

1Is always on.2Sometimes comes on.3Comes on only once.4Does not come on.
When does it come on?
Ignition key
position
1Lock2Acc3On (before starting engine)4Start5On after starting (Engine: run)
6On after starting (Engine: stop)
Timing
1Immediately after ignition is on.2Immediately after ignition starts.
3When advancing (Speedmiles/h,miles/h)4While traveling at a constant speed (Speedmiles/h)
5When decelerating (Speedmiles/h,miles/h)
6When turning (To right, to left, steering angledeg., steering timesec)
7When other electrical parts move (Part name:, Operating condition)
8When moving other electrical parts (Part name:, Operating condition)
2. SYMPTOMS
ABS operating
condition1Performs no work.2Operates only when abruptly applying brakes. (Conditions: vehicle speedmiles/h, how to step
on brake pedal)
3Operating time (sec., etc.)4Operating noise (Produced/Not produced)
5What kind of noise? (Knock, gong gong, bong, buzz, gong gong buzz, etc.)
6Reaction force of brake pedal (Stick, pressed down once with a clunk, pressed and released, etc.)
TCS operating
condition
1Performs no work.2Operates only when abruptly accelerating. (Conditions: vehicle speedmiles/h, how to step on
accelerator pedal)
3Operating time (sec., etc.)4Operating noise (Produced/Not produced)
5What kind of noise? (Knock, gong gong, bong, buzz, gong gong buzz, etc.)
6Whether or not operation indicator light comes on. (Come on/Does not come on, Others)
Behavior of
vehicle
1Directional stability cannot be obtained or steering arm refuses to work when applying brakes (vehicle turns to right, turns
to left, spins, etc.).
2Directional stability cannot be obtained or steering arm refuses to work when accelerating (vehicle turns to right, turns to
left, spins, etc.).
3Brakes are out of order (braking distance is long, brakes lock or drag, pedal stroke is long, pedal sticks, etc.).
4Poor acceleration (fails to accelerate, engine stalls, etc.).
5Vibration, abnormal noise (operating noise is loud, noise is produced during operation from the front of vehicle (right, left)
(tones:), noise is produced during operation from the rear of vehicle (tones:, others)
6Other phenomena (concrete symptoms)
3. CONDITIONS UNDER WHICH TROUBLE OCCURS
Environment1Weather (fine, cloudy, rain, snow, etc.)
2Ambient temperature (°C/°F)
3Road (urban area, suburbs, highway, general road, ascending slope, descending slope, paved road, gravel road, muddy
road, sandy place, etc.)
4Road surface (dry, wet, new-fallen snow, compressed snow, frozen slope, etc.)
Conditions
1Brakes (decelerationg, continuous/intermittent)2Accelerator (accelerationg, continuous/intermittent)
3Travel speed (miles, advancing, accelerating, reducing speed, low speed, turning, etc.)
4Condition of tire of each wheel (air pressure, degree of wear, whether or not genuine parts are used, whether
or not chain is passed around tires, whether or not T tire is used.) others ()
5Condition of suspension alignment ()
6Loading state ()
4. REPAIRED PARTS ARE USED OR NOT
15
4-4bBRAKES
6. Diagnostics Chart for On-board Diagnosis System

11. General Diagnostics Table
: Primary expected causes: Secondary expected causes
Trouble conditions
SymptomsHydraulic
unit
Speed sensor
P valve
Master cylinder
Calipers and piston
Pad
Rotor
Hand brake
Piping
Mixture of air
Brake booster and check valve
Axle and wheel
Alignment
Play of pedal
Rough road surface
Semicylindrical road surface
Loose or worn suspension
Tire
Wrong connection and wiring
Stroke sensor Solenoid valve
Motor
Mount bush ABS function
Directional stability cannot be
obtained when braking.Vehicle turns to right or left. 
Vehicle spins.
Out-of-order brakesLong braking distance
 
Brakes lock.  
Brakes drag.
Long pedal stroke  
Abnormal vehicle pitching 
Unstable braking force. One-
side brake refuses to work. 
TCS function
When accelerating abruptly,
directional stability cannot be
obtained when traveling on a
slippery road surface.Vehicle moves unsteadily.
Handle refuses to work.
Handle loses control. 
Bad acceleration, engine stall-
ing (In addition to the causes
listed here, check the ECM
specifications.)Engine stalls. Engine speed
fails to increase.
Engine speed increases sud-
denly.
Vibration occurs and abnormal
noise is produced.

When applying brakes abruptly.

When accelerating abruptly.

When driving on a slippery
road surface.Brake pedal heavily vibrates
when applying brakes.
   
Loud hydraulic unit operating
noise
Noise is produced from front
of vehicle.
Noise is produced from rear of
vehicle.
NOTE:
This list includes no engine failure and transmission failure.
127
4-4bBRAKES
11. General Diagnostics Table

B: CHECK LIST FOR INTERVIEW
Check the following items about the vehicle’s state.
1. THE STATE OF THE WARNING LIGHTS
a. ABS warning light

1Is always on.2Sometimes comes on.3Comes on only once.4Does not come on.
When/how long does it come on?
Ignition key
position
1Lock2Acc3On (before starting engine)4Start5On after starting (Engine: run)

6On after starting (Engine: stop)
Timing
1Immediately after ignition is on.2Immediately after ignition starts.

3When advancing (Speedmiles/h,miles/h)4While traveling at a constant speed (Speedmiles/h)

5When decelerating (Speedmiles/h,miles/h)

6When turning (To right, to left, steering angledeg., steering timesec)

7When moving other electrical parts (Part name:, Operating condition)
2. SYMPTOMS
ABS operating
condition1Performs no work.2Operates only when abruptly applying brakes. (Conditions: vehicle speedmiles/h, how
to step on brake pedal
)

3Operating time (sec., etc.)4Operating noise (Produced/Not produced)

5What kind of noise? (Knock, gong gong, bong, buzz, gong gong buzz, etc.)

6Reaction force of brake pedal (Stick, pressed down once with a clunk, pressed and released, etc.)
Behavior of
vehicle
1Directional stability cannot be obtained or steering arm refuses to work when applying brakes (vehicle turns to
right, turns to left, spins, etc.
).

2Directional stability cannot be obtained or steering arm refuses to work when accelerating (vehicle turns to right,
turns to left, spins, etc.
).

3Brakes are out of order (braking distance is long, brakes lock or drag, pedal stroke is long, pedal sticks, etc.
).

4Poor acceleration (fails to accelerate, engine stalls, etc.).

5Vibration, abnormal noise (operating noise is loud, noise is produced during operation from the front of vehicle
(right, left) (tones:
), noise is produced during operation from the rear of vehicle (tones:, others
)

6Other phenomena (concrete symptoms)
3. CONDITIONS UNDER WHICH TROUBLE OCCURS
Environment1Weather (fine, cloudy, rain, snow, etc.)

2Ambient temperature (°C/°F)

3Road (urban area, suburbs, highway, general road, ascending slope, descending slope, paved road, gravel road,
muddy road, sandy place, etc.
)

4Road surface (dry, wet, new-fallen snow, compressed snow, frozen slope, etc.)
Conditions
1Brakes (decelerationg, continuous/intermittent)2Accelerator (accelerationg, continuous/intermittent)

3Travel speed (miles, advancing, accelerating, reducing speed, low speed, turning, etc.)

4Condition of tire of each wheel (air pressure, degree of wear, whether or not genuine parts are used,
whether or not chain is passed around tires, whether or not T tire is used.) others (
)

5Condition of suspension alignment ()

6Loading state ()
4. REPAIRED PARTS ARE USED OR NOT
11
4-4cBRAKES [ABS 5.3 TYPE]
6. Diagnostics Chart for On-board Diagnosis System

11. General Diagnostics Table
A: SYMPTOMS AND PROBABLE CAUSES
Symptom Probable faulty units/parts
Vehicle instability during brakingVehicle pulls to either side.
Hydraulic unit (solenoid valve)

ABS sensor

Brake (caliper & piston, pads)

Wheel alignment

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections

Road surface (uneven, camber)
Vehicle spins.
Hydraulic unit (solenoid valve)

ABS sensor

Brake (pads)

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections
Poor brakingLong braking/stopping distance
Hydraulic unit (solenoid valve)

Brake (pads)

Air in brake line

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections
Wheel locks.
Hydraulic unit (solenoid valve, motor)

ABS sensor

Incorrect wiring or piping connections
Brake dragging
Hydraulic unit (solenoid valve)

ABS sensor

Master cylinder

Brake (caliper & piston)

Parking brake

Axle & wheels

Brake pedal play
Long brake pedal stroke
Air in brake line

Brake pedal play
Vehicle pitching
Suspension play or fatigue (reduced damping)

Incorrect wiring or piping connections

Road surface (uneven)
Unstable or uneven braking
Hydraulic unit (solenoid valve)

ABS sensor

Brake (caliper & piston, pads)

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections

Road surface (uneven)
Vibration and/or noise (while
driving on slippery roads)Excessive pedal vibration
Incorrect wiring or piping connections

Road surface (uneven)
Noise from hydraulic unit
Hydraulic unit (mount bushing)

ABS sensor

Brake piping
Noise from front of vehicle
Hydraulic unit (mount bushing)

ABS sensor

Master cylinder

Brake (caliper & piston, pads, rotor)

Brake piping

Brake booster & check valve

Suspension play or fatigue
Noise from rear of vehicle
ABS sensor

Brake (caliper & piston, pads, rotor)

Parking brake

Brake piping

Suspension play or fatigue
272
4-4cBRAKES [ABS 5.3 TYPE]
11. General Diagnostics Table