Mitsubishi Evolution X. Manual — part 874

ON-VEHICLE SERVICE

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POWER STEERING

37-19

POWER STEERING SYSTEM AIR BLEEDING

M1372002200909

Perform air bleeding procedure as necessary after replacing
the steering gear or the steering fluid lines.
1. Raise and support the front wheels.

AC705444 AB

Crank angle sensor

Oil filter

2. Disconnect the crank angle sensor connector.

CAUTION

Perform air bleeding only while cranking the engine. If air
bleeding is performed while the engine is running, air
could enter the fluid. During air bleeding, refill the steering
fluid supply so that the level never falls below the lower
mark on the dipstick.
3. Turn the steering wheel all the way to the left and right five

or six times while using the starter motor to crank the engine
intermittently several times (for 15 to 20 seconds).

4. Connect the crank angle sensor connector.
5. Start the engine (idling).
6. Turn the steering wheel to the left and right until there are no

air bubbles in the oil reservoir.

7. Confirm that the fluid is not milky, and that the level is

between the high and low dipstick marks.

8. Confirm that there is very little change in the fluid level when

the steering wheel is turned left and right.

CAUTION

If the fluid level rises suddenly after the engine is stopped,
the air has not been completely bled. If air bleeding is not
complete, there will be abnormal noises from the pump
and the flow-control valve, and this condition could cause
reduce the life of the power steering components.

AC608306

With engine stopped

AC

Fluid level change: Within 5 mm (0.2 in)

With engine running

9. Confirm that the change in the fluid level is no more than 5

mm (0.2 inch) when the engine is stopped and when it is
running.

10.If the change of the fluid level is 5 mm (0.2 inch) or more,

the air has not been completely bled from the system. The
air bleeding procedure must be repeated.

AC608435 AD

MUT-III main harness A

V. C. I.

USB cable

Data link connector

ON-VEHICLE SERVICE

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POWER STEERING

37-20

11.Use the scan tool MB991958, check if the DTC is set. If it is

set, erase it.

OIL PUMP PRESSURE TEST

M1372002300757

Required Special Tools:

• MB990662: Power Steering Oil Pressure Gauge

• MB991548: Power Steering Oil Pressure Gauge Adapter

(Pump Side)

•

AC609397AB

Thermometer

Reservoir

Pressure gauge
(MB990662)

Shut-off valve

Adapter
(MB991548)

Oil
pump

Adapter
(MB991549)

MB991549: Power Steering Oil Pressure Gauge Adapter
(Hose Side)

1. Disconnect the pressure hose from the oil pump, and then

connect the special tools MB991548, MB990662 and
MB991549.

2. Bleed air, then turn the steering wheel several times while

the vehicle is not moving so that the temperature of the fluid
rises to approximately 50

− 60° C (122 − 140° F).

3. Start the engine and idle it at 1000

± 100 r/min.

CAUTION

The pressure gauge shut-off valve must not remain closed
for more than 10 seconds.
4. Fully close the shut-off valve of the pressure gauge and

measure the oil pump relief pressure to confirm that it is
within the standard value range. Open it again immediately
after checking the pressure.

Standard value: 8.1

− 8.8 MPa (1,174 − 1,276 psi)

5. If it is not within the standard value, replace the oil pump.
6. Check whether or not the hydraulic pressure is the standard

value when no-load conditions are created by fully opening
the shut-off valve of the pressure gauge.

Standard value: 1.0 MPa (144 psi)

ON-VEHICLE SERVICE

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POWER STEERING

37-21

7. If it is not within the standard value, the probable cause is a

malfunction of the oil line or steering gear, so check these
parts and repair as necessary.

8. Turn the steering wheel all the way to the left or right; then

check whether or not the retention hydraulic pressure is the
standard value.

Standard value: 8.1

− 8.8 MPa (1,174 − 1,276 psi)

9. If not the standard value, overhaul the steering gear.

Remeasure fluid pressure.

10. Remove the special tools MB991548, MB990662 and

MB991549, and then tighten the pressure hose to the
specified torque.

Tightening torque: 57

± 7 N⋅ m (42 ± 5 ft-lb)

11. Bleed the system (Refer to

P.37-19

).

POWER STEERING PRESSURE SWITCH CHECK

M1372007200647

Required Special Tools:

• MB990662: Power Steering Oil Pressure Gauge

• MB991548: Power Steering Oil Pressure Gauge Adapter

(Pump Side)

•

ACX01134 AH

Thermo-
meter

Adapter
(MB991548)

Oil
pump

Adapter
(MB991549)

Shut-off
valve

Pressure
gauge
(MB990662)

Reservoir

MB991549: Power Steering Oil Pressure Gauge Adapter
(Hose Side)

1. Disconnect the pressure hose from the oil pump, and then

connect the special tools MB991548, MB990662 and
MB991549.

2. Bleed air, and then turn the steering wheel several times

while the vehicle is not moving so that the temperature of
the fluid rises to approximately 50

° C − 60° C (122° F −

140

° F).

3. The engine should be idling.
4. Disconnect the connector for the oil pressure switch, and

place an ohmmeter at the switch.

5. Gradually close the shut-off valve of the pressure gauge and

increase the hydraulic pressure, then check whether or not
the hydraulic pressure that activates the switch is the
standard value.

Standard value: 8.1

− 8.8 MPa (1,174 − 1,276 psi)

6. Gradually open the shut-off valve and reduce the hydraulic

pressure; then check whether or not the hydraulic pressure
that deactivates the switch is the standard value.

Standard value: 8.1

− 8.8 MPa (1,174 − 1,276 psi)

7. Remove special tools MB991548, MB990662 and

MB991549, connect the pressure hose to the oil pump, and
then tighten the eye bolt to the specified torque.

Tightening torque: 57

± 7 N⋅ m (42 ± 5 ft-lb)

8. Bleed the system. (Refer to

P.37-19

).

STEERING WHEEL

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POWER STEERING

37-22

STEERING WHEEL

REMOVAL AND INSTALLATION

M1372011401078

CAUTION

• Before removing the steering wheel assembly and driver's air bag module, always refer to GROUP

52B

− Service Precautions

P.52B-25

and Air bag Module and Clock Spring

P.52B-386

.

• After removing the steering wheel, always perform a calibration for the ASC-ECU to learn the

steering wheel sensor neutral point. (Refer to GROUP 35C

− On-vehicle Service, Steering Wheel

Sensor Calibration

P.35C-267

.)

Pre-removal Operation
Steering wheel at straight-ahead position check

Post-installation Operation
• Steering wheel at straight-ahead position check

• Steering wheel looseness check

AC708304 AB

1

7

18

8

2

3

4

1

9

44 ± 11 N·m
33 ± 8 ft-lb

Craw

5

10

8

2

3

4

6

11

13

16

17

18

9.5 ± 2.5 N·m
84 ± 22 in-lb

14

15

Craw

12

9.5 ± 2.5 N·m
84 ± 22 in-lb

Removal steps

<<

A

>>

1. Cover

>>

B

<<

2. Horn connector connection

>>

B

<<

3. Steering switch connector

connection

<<

B

>>

>>

B

<<

4. Driver’s air bag module

connector connection

5. Steering wheel voice control

switch cover <Vehicles with
steering wheel voice control
switch>

6. Steering wheel voice control

switch connector connection
<Vehicles with steering wheel
voice control switch>

7. Steering wheel voice control

switch <Vehicles with steering
wheel voice control switch>

<<

C

>>

>>

A

<<

8. Driver’s air bag module
9. Flunge nut
10. Lower cover

Removal steps (Continued)