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19 - 30
PUMP
PUMP (Continued)
Fig. 2 Power Steering Pump - 2.7L Engine
1 - SUPPLY FITTING
2 - PUMP SHAFT
3 - PULLEY
4 - PRESSURE FITTING
As the high pressure area is filled, oil flows under
the vanes in the rotor slots, forcing the vanes to fol-
low the inside surface of the cam ring. As the vanes
reach the restricted area of the cam ring, oil is forced
out from between the vanes. When excess oil flow is
generated during high-speed operation, a regulated
amount of oil 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.
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
oil to flow through a trigger orifice located in the out-
let fitting. This reduces pressure on the spring end of
the flow control valve which then opens and allows
the oil 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.
STANDARD PROCEDURE - 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 ATF+4 Automatic Transmis-
sion Fluid (MS-9602). Do not overfill.
(1) Wipe
the
reservoir
removal.
(2) Fill the pump fluid reservoir to the proper
level. The fluid level should be within the "FILL
RANGE" listed on the exterior of the reservoir when
the fluid is at normal ambient temperature, approxi-
mately 21°C to 27°C (70°F to 80°F).
(3) Let the fluid settle in the system for at least
two (2) minutes.
(4) Start the engine and let run for a few seconds.
Then turn the engine off.
(5) Add fluid if necessary. Repeat the above proce-
dure until the fluid level remains constant after run-
ning the engine.
(6) Raise the front wheels off the ground.
(7) Start the engine. Slowly turn the steering
wheel right and left, lightly contacting the wheel
stops.
(8) Add power steering fluid if necessary.
(9) Lower the vehicle and turn the steering wheel
slowly from lock to lock.
(10) Stop the engine. Check the fluid level and
refill as required.
(11) If the fluid is extremely foamy, allow the vehi-
cle to stabilize a few minutes, then repeat the above
procedure.
REMOVAL
REMOVAL - PUMP (2.0L/2.4L ENGINE)
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, OR ALLOW HOSES TO
TOUCH HOT EXHAUST MANIFOLD OR CATALYST.
(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 clamp, then fluid supply hose from
fitting on pump. Install a cap on fitting.
(4) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(5) Remove the accessory drive splash shield.
JR
fill
cap
clean
before
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