Suzuki Grand Vitara JB627. Service manual — part 260

6C-1 Power Assisted Steering System:

Steering

Power Assisted Steering System

Precautions

P/S System Note

S6JB0B6300001

NOTE

• Some parts in the power steering gear case cannot be disassembled or adjusted. For detailed

information, refer to the description of “Steering Gear Case Construction”.

• All steering gear fasteners are important attaching parts in that they could affect the performance of

vital parts and systems, and/or could result in major repair expense. They must be replaced with one
of the same part number or with an equivalent part if replacement becomes necessary. Do not use a
replacement part of lesser quality or substitute design. Torque values must be used as specified
during reassembly to assure proper retention of these parts.

• Although the figures in this section show only the left-hand steering vehicle, the same work

procedure and data apply to the right-hand steering vehicle.

General Description

P/S System Construction

S6JB0B6301001

The power steering (P/S) system in this vehicle reduces the driver’s effort needed in turning the steering wheel by
utilizing the hydraulic pressure generated by the power steering (P/S) pump (2) which is driven by the engine.
It is an integral type with the rack and pinion gears and the control valve unit, hydraulic pressure cylinder unit all built in
the steering gear case (1).

3

2

1

3

2

1

[A]

[B]

I6JB0B630001-03

[A]: LHD model
[B]: RHD model

3. P/S fluid reservoir

Power Assisted Steering System: 6C-2

Steering Gear Case Construction

S6JB0B6301002

The steering gear case consists of two sections: one including a cylinder and the other a valve. Main components of
the cylinder section are a gear case (7), a rack (8) and a tube and those of the valve section are a valve case (10), a
sleeve (4) and a stub shaft (2). The sleeve is linked with the pinion (6) through a pin (1) and the valve and stub shaft
are integrated into one unit. Then the pinion and the stub shaft are linked to each other by means of the torsion bar (3).
Thus, when the stub shaft moves, the valve changes its position, thereby switching the hydraulic passage from the
pump to the cylinder to help steering operation.
When turning the steering wheel feels heavy due to P/S fluid leakage or for some other reason (i.e., when in the
manual steering mode), the stub shaft and pinion are in direct linkage and the force is output directly through the
pinion and rack.

P/S Pump Construction

S6JB0B6301003

The power steering pump is a vane type and is driven by the V-ribbed belt from the crankshaft.

Power steering (P/S) pump specifications

Flow Control Valve (Relief Valve)
As the discharge rate of the P/S pump increases in proportion to the pump revolution speed, a flow control valve is
added to control it so that the optimum amount of fluid for steering operation is supplied according to the engine speed
(driving condition).

5. Bearing

9. Ferrule

1

3

2

4

9

5

6

7

10

8

I5JB0A630002-01

Model

Vane type

Hydraulic pressure
control

Relieved
pressure

7850 kPa (78.5 kg/cm

2

, 1116 psi)

Control device

Flow control valve and relief valve

Power steering pressure switch

Switch turns on (closes) when the pressure is higher than 2500 –
3000 kPa (25 – 30 kg/cm

2

, 356 – 427 psi).

ECM uses this signal for idle speed control.

6C-3 Power Assisted Steering System:

Schematic and Routing Diagram

P/S Fluid Flow Diagram

S6JB0B6302001

IYSQ01630002-01

1. Power steering pump

3. P/S fluid reservoir

5. Pinion

2. Valve section

4. Rack

6. Cylinder

Power Assisted Steering System: 6C-4

Diagnostic Information and Procedures

P/S System Symptom Diagnosis

S6JB0B6304001

Condition

Possible cause

Correction / Reference Item

Steering wheel feels
heavy (at low speed)

Fluid deteriorated, low viscosity,
different type of fluid mixed

Replace fluid.

Pipes or hoses deformed, air entering
through joint

Replace defective part.

Insufficient air purging from P/S circuit

Purge air.

P/S belt worn, lacking in tension

Adjust belt tension or replace belt as
necessary.

Tire inflation pressure excessively low

Inflate tire.

Front end alignment out of order

Check and adjust front end alignment.

Steering wheel installed improperly
(twisted)

Install steering wheel correctly.

Bind in tie-rod or tie-rod end ball joint

Replace defective part.

P/S pump hydraulic pressure fails to
increase

Check pressure and repair or replace defective
part.

P/S pump hydraulic pressure increases
but slowly

Check pressure and repair or replace defective
part.

Steering gear case malfunction

Replace gear case.

Steering wheel feels
heavy momentarily when
turning it to the left or
right

Air drawn in due to insufficient amount of
fluid

Add fluid and purge air.

Slipping P/S belt

Adjust belt tension or replace belt as
necessary.

P/S pump hydraulic pressure fails to
increase

Check pressure and repair or replace defective
part.

P/S pump hydraulic pressure increases
but slowly

Check pressure and repair or replace defective
part.

Steering gear case malfunction

Replace gear case.

Poor recovery from turns Deformed pipes or hoses

Replace defective part.

Steering column installed improperly

Install steering column correctly.

Front end alignment out of order

Check and adjust front end alignment.

Ball joints binding

Replace defective part.

P/S pump hydraulic pressure fails to
increase

Check pressure and repair or replace defective
part.

P/S pump hydraulic pressure increases
but slowly

Check pressure and repair or replace defective
part.

Steering gear case malfunction

Replace gear case.

Vehicle pulls to one side
during straight driving

Mismatched or uneven tire

Replace tire.

Low or uneven tire inflation pressure

Inflate tires to proper pressure or adjust right
and left tires inflation pressure.

Brake dragging in one wheel

Repair.

Front end alignment out of order

Check and adjust front end alignment.

Rear end alignment out of order

Check and adjust rear end alignment.

Malfunction of control valve in gear case Replace gear case.

Steering wheel play is
large and vehicle wanders

Refer to “Steering Symptom Diagnosis
in Section 6A”.

Fluid leakage

Loose joints of (hydraulic pressure)
pipes and hoses

Retighten.

Deformed or damaged pipes or hoses

Replace defective part.