CHEVROLET DYNASTY 1993 Service Manual

POWER STEERING SERVICE DIAGNOSIS
Ä STEERING 19 - 3

POWER STEERING SERVICE DIAGNOSIS
19 - 4 STEERING Ä

POWER STEERING SERVICE DIAGNOSIS
Ä STEERING 19 - 5

POWER STEERING SERVICE DIAGNOSIS
19 - 6 STEERING Ä

POWER STEERING SERVICE DIAGNOSIS
Ä STEERING 19 - 7

POWER STEERING SERVICE DIAGNOSIS
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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. The high pressure lifts the re-
lief valve ball from its seat and allows oil 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 oil to
return to the intake side of the pump. This action
limits maximum pressure output of the pump to a
safe level. Under normal power steering pump operating con-
ditions, pressure requirements of the pump are below
maximum, causing the pressure relief valve to re-
main closed.
CHECKING POWER STEERING FLUID LEVEL
WARNING: FLUID LEVEL SHOULD BE CHECKED
WITH ENGINE OFF TO PREVENT INJURY FROM
MOVING PARTS. DO NOT USE AUTOMATIC TRANS-
MISSION FLUID IN THE POWER STEERING SYS-
TEM. DO NOT OVERFILL THE POWER STEERING
SYSTEM.
Wipe reservoir filler cap free of dirt, before check-
ing power steering fluid level. The dipstick should in- dicate FULL COLD when fluid is at normal ambient
temperature, approximately 21ÉC to 27ÉC (70ÉF to
80ÉF). In all pumps add fluid as necessary to obtain
proper level, using only MopartPower Steering
Fluid, or equivalent. DO NOT USE ANY TYPE
OF AUTOMATIC TRANSMISSION FLUID.
POWER STEERING PUMP PRESSURE TEST
The following procedure can be used to test the op-
eration of the power steering system on the vehicle. (1) Check power steering pump drive belt tension
and adjust as necessary. (2) Disconnect power steering fluid pressure hose,
at steering gear or power steering pump. Use a con-
tainer for dripping fluid. (3) Connect Pressure Gauge, Special Tool C-3309-E
(Fig. 1) to both hoses using adapter fittings. Connect
spare pressure hose to gear or pump. (4) Completely open valve on Special Tool
C-3309-E (Fig. 1). (5) Start engine and let idle.
(6) Check power steering fluid level, and add fluid
as necessary. (7) Gauge should read below 862 kPa (125 psi), if
above, inspect the hoses for restrictions and repair as
necessary. The initial pressure should be in the
range of 345-552 kPa (50-80 psi).
PUMP LEAKAGE DIAGNOSIS
Ä STEERING 19 - 9

CAUTION: The following test procedure involves test-
ing power steering pump maximum pressure output
and flow control valve operation. Do not leave valve
closed for more than 5 seconds as the pump could be
damaged.
(8) Close valve fully three times and record highest
pressure indicated each time. All three readings
must be above specifications and within 345 kPa
(50 psi) of each other. Power steering pump maximum relief pressure
is 8275 to 8975 kPa (1200 to 1300 psi.).
² Power steering pump pressures above specifications
but not within 345 kPa (50 psi) of each other, replace
pump.
² Pressures within 345 kPa (50 psi) of each other but
below specifications, replace pump.
CAUTION: Do not force the pump to operate against
the stops for more than 5 seconds at a time because,
pump damage will result.
(9) Open test valve. Turn steering wheel to the
extreme left and right positions until against the stops,
recording the highest indicated pressure at each posi-
tion. Compare pressure gauge readings to power steer-
ing pump specifications. If highest output pressures
are not the same against either stop, the steering gear
is leaking internally and must be replaced.
POWER STEERING PRESSURE SWITCH
New for 1993 M.Y., is the use of an idle quality power
steering pressure switch on some front wheel drive
passenger car applications. The purpose of this switch is to signal the power
train control module, that the power steering system is
putting additional load on the engine. This type of
condition exists when turning the front tires of the
vehicle, when the vehicle is stationary and the engine
is at idle speed. When this condition is sensed by the
power train control module, through a signal from the power steering pressure switch, engine idle
speed is increased. This increase in engine idle speed
compensates for the additional load, thus maintain-
ing the require engine idle speed and idle quality.
The power steering pressure switch is mounted to
the power steering pressure hose on the applications
that require its usage. Refer to (Fig. 1 and 2) below
for the pressure switch location on the different en-
gine applications.
REMOVE
(1) Locate power steering pressure switch on power
steering pressure hose. Refer to (Fig. 1 and 2) for the
engine application showing the location of the power
steering switch. (2) Remove vehicle wiring harness connector from
the power steering pressure switch. (3) Remove power steering pressure switch, from
power steering pressure hose.
Fig. 1 Power Steering Pressure Switch Location 3.0L
Fig. 2 Power Steering Pressure Switch Location 3.3 & 3.8L
Fig. 1 Pressure Test Gauge
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INSTALL
(1) Install power steering pressure switch into fit-
ting on power steering pressure hose by hand until
fully seated. Then torque power steering pressure
switch to 12 N Im (106 in. lbs.).
(2) Install vehicle wiring harness connector onto
power steering pressure switch. Be sure latch on wir-
ing harness connector is fully engaged with locking
tab on power steering pressure switch.
CAUTION: Do not use automatic transmission fluid
in power steering system. Only use Mopar T, Power
Steering Fluid, or equivalent.
(3) Fill power steering pump reservoir to correct
fluid level. (4) Connect negative cable back on negative post of
battery. (5) Start engine and turn steering wheel several
times from stop to stop to bleed air from fluid in sys-
tem. Stop engine, check fluid level, and inspect sys-
tem for leaks. See Checking Fluid Level.
POWER STEERING HOSES
Service all power steering hoses with the vehicle
raised on a hoist. Cap all open ends of hoses, power
steering pump fittings and steering gear ports to pre-
vent entry of foreign material into the components.
WARNING: POWER STEERING OIL, ENGINE PARTS
AND EXHAUST SYSTEM MAY BE EXTREMELY HOT
IF ENGINE HAS BEEN RUNNING. DO NOT START
ENGINE WITH ANY LOOSE OR DISCONNECTED
HOSES. DO NOT ALLOW HOSES TO TOUCH HOT
EXHAUST MANIFOLD OR CATALYST.
For part reference and part location on the vehicle
being serviced, refer to Figs. 3 to 6. These show the
hose bracket locations, hose routings and fitting loca-
tions by the engine application of the vehicle. Use
these figure numbers when referring to the removal
or installation procedures for the power steering
hoses listed below.
REMOVAL
(1) Remove vehicle's wiring harness connector (if
applicable to vehicle being serviced) from the power
steering pressure switch (Fig .1&2).
(2) Remove bolts from power steering hose routing
brackets to crossmember attachment points. (3) Disconnect power steering hose at opening clos-
est to power steering gear assembly. Drain power
steering fluid from power steering pump and hose
through open end of hose. (4) Disconnect opposite end of hose and remove
power steering hose assembly from vehicle. (5) Discard O-ring or sealing washer located at end
of tube. (6) Remove power steering pressure switch, from
the removed power steering hose for installation into
the replacement power steering hose.
INSTALLATION
(1) Install the removed power steering pressure
switch into replacement power steering pressure
hose. Torque power steering pressure switch to 12
N Im (106 in. lbs.).
Fig. 3 Power Steering Hose Routing 2.2 & 2.5L
Fig. 4 Power Steering Hose Routing 3.0L
Ä STEERING 19 - 11

(2) Using a lint free towel, wipe clean open power
steering hose ends, power steering pump and steer-
ing gear ports. (3) Install new O-rings or sealing washers on the
ends of the power steering hoses. Lubricate O-rings
or sealing washers using clean power steering fluid. (4) Attach power steering hose to proper connec-
tions at power steering pump and steering gear. Cor-
rectly route power steering hoses avoiding tight
bends or kinking of the hose. Install power steering hose to crossmember routing bracket.
Hoses must
remain away from exhaust system, vehicle com-
ponents and unfriendly surfaces causing pos-
sible damage to power steering hoses. (5) Tighten all fasteners shown for specific applica-
tions in (Fig. 1 to 4) to their correct torques listed
below:
² Pump End Banjo Bolt Ð 34 N Im (25 ft. lbs.)
² Pump End Tube Nut Ð 34 N Im (25 ft. lbs.)
² Gear End Tube Nuts (2) Ð 34 N Im (25 ft. lbs.)
² Crossmember Bracket Bolt Ð 23 N Im (17 ft. lbs.)
² Pump Bracket Nut Ð 40 N Im (30 ft. lbs.)
² Gear Bracket Bolt Ð 68 N Im (50 ft. lbs.)
(6) Install vehicle's wiring harness connector (if ap-
plicable to vehicle being serviced) onto the power
steering pressure switch (Fig .1&2).
(7) When used, protective sponge sleeves must be
properly positioned on power steering hoses. This is to
prevent hose contact with other components. (8) After hose is installed, check for leaks. (See
Pump Installation).
POWER STEERING PUMP REMOVAL
WARNING: POWER STEERING OIL, ENGINE COMPO-
NENTS AND EXHAUST SYSTEM MAY BE EX-
TREMELY HOT IF ENGINE HAS BEEN RUNNING. DO
NOT START ENGINE WITH ANY LOOSE OR DISCON-
NECTED HOSES, OR ALLOW HOSES TO TOUCH HOT
EXHAUST MANIFOLD OR CATALYST.
2.2 & 2.5 LITER
REMOVE
(1) Remove battery cable from (-) negative post on
battery and isolate cable. (2) Loosen power steering pump adjustment bolt
and rotate power steering pump forward in bracket.
Remove power steering pump drive belt from power
steering pump (Fig. 1). It is not necessary to remove
power steering pump drive belt from engine. (3) Raise vehicle See Hoisting, Group 0. Remove
hose clamp and low pressure fluid hose from power
steering pump (Fig. 2). (4) Remove power steering fluid pressure line (Fig.
2) from power steering pump. Drain excess power
steering fluid from line. (5) Loosen but do not remove nut, holding back of
power steering pump to its mounting bracket (Fig. 3).
Then remove bolt attaching pulley side of power steer-
ing pump to the mounting bracket (Fig. 3). (6) Lower Vehicle. Then remove bolt, retaining
power steering pump in adjusting slot of power steer-
ing pump mounting bracket (Fig. 3). (7) Remove power steering pump from top of engine
compartment, using the following procedure.
Lifting power steering pump out of mounting
Fig. 5 Power Steering Hose Routing 3.3 & 3.8L
Fig. 6 Power Steering Hose Routing Turbo III
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