hydraulic pressure for operation of the power steer-
ing gear is provided by a belt driven power steering
pump (Fig. 1). It is mounted on the back side of the
engine, above the front suspension crossmember.

Early production vehicles are equipped with vari-

able-assist power steering pumps. Later production
vehicles are equipped with standard power steering
pumps only.

Vehicles that are equipped with variable-assist

power steering use a droop flow style power steering
pump. The droop flow power steering pump is a con-
stant displacement vane type, but has a variable flow
rate. This provides the speed-sensitive variable-assist
power steering. The variable-assist power steering
pump can be easily identified by the type of power
steering fluid pressure hose fitting connection. While
standard pumps use a standard tube fitting, vari-
able-assist power steering pumps use a banjo style
fitting (Fig. 2).

The power steering pump uses a remote mounted

reservoir for storage of the power steering fluid.

Because of unique shaft bearings, flow control lev-

els or pump displacements, power steering pumps
may be used only on specific vehicle applications. Be
sure that the power steering pump is only replaced
with a pump that is the correct replacement for that
specific application.

OPERATION

Hydraulic pressure is provided for operation of the

power steering gear by the belt driven power steering
pump. The power steering pump is connected to the
steering gear by a power steering fluid pressure hose,
return hose, power steering fluid cooler and remote
power steering fluid reservoir.

Rectangular pumping vanes in the shaft driven

rotor move power steering fluid from the intake to
the cam ring pressure cavities of the power steering
pump. As the rotor begins to turn, centrifugal force
throws the vanes against the inside surface of the
cam ring to pick up residual fluid. This fluid is then

Fig. 1 Power Steering Pump

1 – POWER STEERING PUMP FLUID SUPPLY FITTING
2 – POWER STEERING PUMP SHAFT
3 – POWER STEERING PUMP HOUSING
4 – POWER STEERING PUMP DISCHARGE FITTING
5 – POWER STEERING PUMP SHAFT SEAL

19 - 22

STEERING

forced into the high pressure area. As more fluid is
picked up by the vanes, the additional fluid is forced
into the cavities of the thrust plate through two
crossover holes in the cam ring and pressure plate.
The crossover holes empty into the high pressure
area between the pressure plate and the housing end
cover.

As the high pressure area is filled, fluid flows

under the vanes in the rotor slots, forcing the vanes
to follow the inside surface of the cam ring. As the
vanes reach the restricted area of the cam ring, fluid
is forced out from between the vanes. When excess
fluid flow is generated during high-speed operation, a
regulated amount of fluid returns to the pump intake
side through a flow control valve. The flow control
valve reduces the power required to drive the pump
and holds down temperature build-up.

The speed-sensitive variable-assist power steering

which is built into the early power steering pump
provides full power steering assist at engine idle. As
engine speed is increased, power assist is gradually
reduced by varying the pump flow rate to provide a
firm, responsive feel to the steering system at higher
vehicle speeds.

When steering conditions exceed maximum pres-

sure requirements, such as when the wheels are
turned against the stops, the pressure built up in the
steering gear exerts pressure on the spring end of the
flow control valve inside the pump. The high pres-
sure lifts the relief valve ball from its seat and allows
fluid to flow through a trigger orifice located in the
outlet fitting. This reduces pressure on the spring
end of the flow control valve which then opens and

allows the fluid to return to the intake side of the
pump. This action limits maximum pressure output
of the power steering pump.

Under normal power steering pump operating con-

ditions, pressure requirements of the pump are below
maximum, causing the pressure relief valve to
remain closed.

In the event of a power steering pump drive belt

failure, manual steering control of the vehicle can
still be maintained without pump assistance. How-
ever, under these conditions, steering effort will be
significantly increased.

POWER STEERING FLUID RESERVOIR

DESCRIPTION

All vehicles equipped with power steering use a

remote mounted reservoir for storage of the power
steering fluid. The power steering fluid remote reser-
voir on the 2.5L engine is mounted to the front side
of the engine above the drive belts, between the cyl-
inder heads.

OPERATION

The power steering fluid reservoir stores fluid for

the power steering system.

SERVICE PROCEDURES

POWER STEERING PUMP INITIAL OPERATION

CAUTION: The fluid level should be checked with
engine off to prevent injury from moving compo-
nents. Use only Mopar

Power Steering Fluid. Do

not use automatic transmission fluid. Do not over-
fill.

Wipe filler cap clean, then check the fluid level.

The dipstick should indicate FULL COLD when the
fluid is at normal temperature of approximately 21°C
to 27°C (70°F to 80°F).

(1) Fill the pump fluid reservoir to the proper level

and let the fluid settle for at least two (2) minutes.

(2) Start the engine and let run for a few seconds.

Then turn the engine off.

(3) Add fluid if necessary. Repeat the above proce-

dure until the fluid level remains constant after run-
ning the engine.

(4) Raise the front wheels off the ground.
(5) Start the engine. Slowly turn the steering

wheel right and left, lightly contacting the wheel
stops.

(6) Add power steering fluid if necessary.
(7) Lower the vehicle and turn the steering wheel

slowly from lock to lock.

Fig. 2 Pressure Hose Fitting

1 – POWER STEERING PUMP
2 – POWER STEERING FLUID SUPPLY HOSE
3 – FLOW CONTROL VALVE FITTING
4 – ABS HYDRAULIC CONTROL UNIT HEAT SHIELD
5 – POWER STEERING PRESSURE HOSE

STEERING

19 - 23

DESCRIPTION AND OPERATION (Continued)

(8) Stop the engine. Check the fluid level and refill

as required.

(9) If the fluid is extremely foamy, allow the vehi-

cle to stabilize a few minutes, then repeat the above
procedure.

REMOVAL AND INSTALLATION

POWER STEERING PUMP
(2.5L ENGINE - EARLY PRODUCTION)

WARNING: POWER

STEERING

FLUID,

ENGINE

COMPONENTS AND EXHAUST SYSTEM MAY BE
EXTREMELY HOT IF ENGINE HAS BEEN RUNNING.
DO NOT START ENGINE WITH ANY LOOSE OR DIS-
CONNECTED

HOSES,

ALLOW

HOSES

TOUCH HOT EXHAUST MANIFOLD OR CATALYST.

REMOVAL

(1) Remove battery cable from (-) negative post on

battery and isolate cable.

(2) Siphon as much power steering fluid as possi-

ble out of the remote power steering fluid reservoir.

(3) Remove the power steering fluid supply hose

from the power steering fluid reservoir (Fig. 3). Fluid
supply hose will be removed with the power steering
pump.

(4) Raise vehicle.
(5) Remove right front tire from vehicle.
(6) Remove accessory drive splash shield (Fig. 4).
(7) Remove the heat shield for the antilock brakes

hydraulic control unit (Fig. 5).

(8) Loosen bolt at adjusting slot in accessory drive

mounting bracket, (Fig. 6) attaching back of power
steering pump to the bracket.

(9) Loosen bolt (Fig. 7) at top of power steering

pump front mounting bracket, attaching it to the
accessory drive bracket.

(10) Loosen bolt at adjustment slot, (Fig. 7) attach-

ing the power steering pump front mounting bracket
to cast aluminum accessory drive bracket on engine.

(11) Move the power steering pump toward the

engine as far as possible.

(12) Remove the power steering fluid pressure

hose from pressure fitting on power steering pump
(Fig. 8). Be careful not to loose the copper sealing

Fig. 3 Supply Hose At Power Steering Fluid

Reservoir

1 – HOSE CLAMP
2 – POWER STEERING FLUID RESERVOIR
3 – POWER STEERING FLUID SUPPLY HOSE

Fig. 4 Accessory Drive Splash Shield

1 – SPLASH SHIELD

Fig. 5 Heat Shield

1 – POWER STEERING PUMP
2 – POWER STEERING FLUID SUPPLY HOSE
3 – FLOW CONTROL VALVE FITTING
4 – ABS HYDRAULIC CONTROL UNIT HEAT SHIELD
5 – POWER STEERING PRESSURE HOSE

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STEERING

SERVICE PROCEDURES (Continued)

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