DIAGNOSIS AND TESTING
STEERING SYSTEM DIAGNOSIS CHARTS
STEERING NOISE
There is some noise in all power steering systems. One of the most common is a hissing sound evident at
standstill parking. Hiss is a very high frequency noise similar to that experienced while slowly closing a water
tap. The noise is present in every valve and results from high velocity fluid passing over the edges of the valve
orifice. There is no relationship between this noise and the performance of the vehicles steering system. Hiss
may be expected when the steering wheel is at the end of its travel or slowly turning when the vehicle is at
a standstill.
CONDITION POSSIBLE CAUSES CORRECTION
Objectionable Hiss Or Whistle 1. Damaged or mispositioned
steering column coupler to dash
panel seal.1. Check for proper seal between
steering column coupler and dash
seal.
2. Noisy valve in power steering
gear.2. Replace steering gear assembly.
3. Mis-routed power steering hose 3. Check for proper routing of power
steering hoses and ensure they do
contact other components.
Rattle Or Clunk 1. Steering gear loose on front
suspension crossmember.1. Check steering gear to front
suspension crossmember mounting
bolts. Tighten to specified torque if
found to be loose.
2. Front suspension crossmember to
frame bolts or studs loose.2. Tighten the front suspension
crossmember attaching bolts or
studs to the specified torque.
3. Tie rod is loose (outer or inner). 3. Check tie rod pivot points for
wear. Replace worn/loose parts as
required.
4. Loose lower control arm to front
suspension crossmember bolts.4. Tighten control arm mounting
bolts to the specified torques.
5. Loose upper control arm/ shock
absorber mounting bracket to body
attaching bolts.5. Check mounting bracket to body
attaching bolts for looseness. If
required tighten to the specified
torques.
6. Power steering fluid pressure
hose touching the body of the
vehicle.6. Adjust hose to proper position by
loosening, repositioning, and
tightening fitting to specified torque.
Do not bend tubing.
7. Noise internal to power steering
gear.7. Replace steering gear assembly.
8. Damaged front suspension
crossmember.8. Replace front suspension
crossmember.
9. Loose stabilizer bar attaching link
mounting nuts.9. Tighten the stabilizer bar attaching
link mounting nuts to the specified
torque.
Chirp or squeal (in the area of the
power steering pump). Particularly
noticeable at full wheel travel and
during standstill parking.1. Loose power steering pump drive
belt.1. Adjust power steering pump drive
belt to specified tension.
19 - 2 STEERINGNS
CONDITION POSSIBLE CAUSES CORRECTION
Power steering pump growl results from the development of high pressure fluid flow. Normally this noise
should not be high enough to be objectionable. Abnormal situations, such as a low oil level causing
aeration or hose touching the vehicle body, can create a noise level that could bring complaints.
WHINE OR GROWL (PUMP
NOISE)1. Low fluid level. 1. Fill power steering fluid
reservoir to proper level and
perform leakage diagnosis.
(Recheck fluid level after power
steering fluid is free of air.)
2. Power steering hose touching
vehicle body or frame.2. Reposition power steering
hose. Replace hose if tube ends
are bent.
3. Extreme wear of power
steering pump internal parts.3. Replace power steering pump
and flush system.
SUCKING AIR SOUND 1. Loose clamp on power steering
fluid low pressure hose.1. Tighten or replace hose clamp.
2. Missing O-Ring on power
steering pressure hose
connection.2. Inspect connection and replace
O-Ring as required.
3. Low power steering fluid level 3. Fill power steering fluid
reservoir to proper level and
perform leakage diagnosis.
4. Air leak between power
steering fluid reservoir and power
steering pump.4. Inspect and/or replace power
steering fluid reservoir or supply
hose as required.
SQUEAK OR RUBBING
SOUND1. Sound coming from steering
column.1.Check for squeak in steering
column. Inspect for contact
between shroud, intermediate
shaft, column, and steering wheel.
Realign if necessary.Note: Check
steering column for noise
without clockspriing installed
and with the steering column
shaft removed from the steering
intermediate shaft. This must be
done before removing the
steering column for a noise
complaint.
2. Check for lack or grease on
steering column dash panel to
lower coupler seal.
2.Clockspring 3. Replace Clockspring
3. Sound internal to steering gear. 4. Replace steering gear
assembly.
SCRUBBING OR KNOCKING
SOUND1. Incorrect tire size. 1. Verify that tire size on vehicle is
the same as originally supplied.
2. Check clearance between tires
and other vehicle components,
through the full travel of the
suspension.2. Correct as necessary.
3. Check for interference between
steering gear and other
components.3.Correct as necessary.
4.Incorrect steering gear supplied. 4. Replace steering gear with
correct steering gear for specific
vehicle.
NSSTEERING 19 - 3
DIAGNOSIS AND TESTING (Continued)
BINDING STICKING SEIZED
SHAKE SHUDDER VIBRATION
CONDITION POSSIBLE CAUSES CORRECTION
CATCHES, STICKS IN CERTAIN
POSITIONS OR IS DIFFICULT TO
TURN.1. Low power steering fluid level. 1. Fill power steering fluid reservoir
to specified level and perform
leakage diagnosis.
2. Tires not inflated to specified
pressure.2. Inflate tires to the specified
pressure.
3. Lack of lubrication in front
suspension lower control arm ball
joints.3. Replace lower ball joint.
4. Worn lower ball joint. 4. Replace the lower ball joint.
5. Lack of lubrication in steering
gear outer tie rod ends.5. Replace tie rod end.
6. Loose power steering pump drive
belt.6. Tighten the power steering pump
drive belt to the specified tension.
See accessory drive in service
manual.
7. Faulty power steering pump flow
control. (Verify cause using Power
Steering Pump Test Procedure.)7. Replace power steering pump.
8. Excessive friction in steering
column or intermediate shaft.8. Correct condition. (See Steering
Column Service Procedure)
9. Steering column coupler binding. 9. Realign the steering column to
eliminate the binding condition.
10. Binding lower ball joint. 10. Replace the lower ball joint.
11. Excessive friction in steering
gear.11. Replace steering gear assembly.
CONDITION POSSIBLE CAUSES CORRECTION
VIBRATION OF THE STEERING
WHEEL AND/OR DASH DURING
DRY PARK OR LOW SPEED
STEERING MANEUVERS.1. Air in the fluid of the power
steering system.1. Steering shudder can be expected
in new vehicles and vehicles with
recent steering system repairs.
Shudder should improve after the
vehicle has been driven several
weeks.
2. Tires not properly inflated. 2. Inflate tires to the specified
pressure.
3. Excessive engine vibration. 3. Ensure that the engine is running
properly.
4. Loose tie rod end. 4. Check the inner to outer tie rod
jam nut for looseness. If loose
tighten to the specified torque.
Inspect inner tie rod for looseness at
steering gear. Inspect outer tie rod
ball for excessive wear/looseness. If
inner tie rod is loose replace steering
gear, if outer tie has excessive wear
replace tie rod end.
5.Overcharged air conditioning
system.5.Check air conditioning pump head
pressure. (See Air Conditioning
Refrigerant System Diagnosis)
19 - 4 STEERINGNS
DIAGNOSIS AND TESTING (Continued)
LOW ASSIST, NO ASSIST, HARD STEERING
POOR RETURN TO CENTER
CONDITION POSSIBLE CAUSES CORRECTION
STIFF, HARD TO TURN, SURGES,
MOMENTARY INCREASE IN
EFFORT WHEN TURNING.1. Tires not properly inflated. 1. Inflate tires to specified pressure.
2. Low power steering fluid level. 2. Add power steering fluid as
required to power steering fluid
reservoir to obtain proper level.
Perform leakage diagnosis on power
steering system.
3. Loose power steering pump drive
belt.3. Tighten the power steering pump
drive belt to the specified tension. If
drive belt is defective, replace and
correctly tension.
4. Lack of lubrication in lower control
arm ball joint.4. Replace lower ball joint.
5. Worn lower ball joint. 5. Replace lower ball joint.
6. Low power steering pump
pressure. (Verify using Power
Steering System Test Procedure)6. Verify cause using the Power
Steering System Test Procedure.
Replace the power steering pump if
necessary.
7. High internal leak in steering gear
assembly.7. Check steering system using the
Power Steering System Test
Procedure. If steering gear is
defective replace steering gear.
CONDITION POSSIBLE CAUSES CORRECTION
STEERING WHEEL DOES NOT
RETURN TO CENTER POSITION.1. Tires not
inflated to specified pressure.1. Inflate tires to specified pressure.
2. Improper front wheel alignment. 2. Check and adjust as necessary.
3. Steering column U-joints
misaligned.3. Realign steering column U-joints.
4. Mispositioned dash cover. 4. Reposition dash cover.
To evaluate items 6 and 7, disconnect
the intermediate shaft. Turn the
steering wheel and feel or listen for
internal rubbing in steering column.
5. Steering wheel rubbing. 5. Adjust steering column shrouds to
eliminate rubbing condition.
6. Damaged, mis-positioned or
un-lubricated steering column coupler
to dash seal.6. Determine condition which exists
and correct.
7. Binding shaft bearing
in steering column assembly.7. Replace the steering column.Note:
Before replacing steering column,
disconnect intermediate steering
coupler from steering column shaft
and remove steering wheel,
clockspring and shrouds from
steering column. This must be done
to verify a binding shaft bearing in
the steering column before
replacing the steering column.
8. Excessive friction in steering
column coupler.8. Replace steering column coupler.
9. Excessive friction in steering gear. 9. Replace steering gear.
10. Excessive friction in front strut
mount bearing10. Replace the strut mount or strut
mount pivot bearing.
NSSTEERING 19 - 5
DIAGNOSIS AND TESTING (Continued)
LOOSE STEERING
CONDITION POSSIBLE CAUSES CORRECTION
EXCESSIVE STEERING WHEEL
KICKBACK OR TOO MUCH
STEERING WHEEL FREE PLAY.1. Air in the fluid of the power
steering system.1. Fill power steering fluid reservoir
to the specified level. Perform
procedure to bleed the air out of the
power steering system. Perform
leakage diagnosis.
2. Steering gear loose on front
suspension crossmember.2. Check steering gear to front
suspension crossmember mounting
bolt torque. Tighten to specified
torque if found to be loose.
3. Worn, broken or loose steering
column to steering gear coupler.3. Check for worn universal joint,
broken isolator or loose fasteners.
4. Free play in steering column. 4.Check components of steering
system and repair or replace as
required. Note: Inspect steering
column with steering wheel installed
and steering column shaft
disconnected from intermediate
coupler. Verify that steering wheel
attaching nut is tightened to the
specified torque. Verify that the 4
mounting nuts for the steering
column are tightened to the specified
torque.
5. Loose lower control arm ball joint. 5. Check and or replace the ball joint
or control arm as required.
6. Loose steering knuckle to lower
ball joint stud attaching nut.6. Check attaching nut and tighten if
required to specified torque.
7. Front wheel bearings loose or
worn.7. Tighten hub nut to specified
torque or replace with new parts as
necessary.
8. Loose outer tie rod ends. 8. Check free play of outer tie rod
ends and replace if required.
9. Loose inner tie rod ends. 9. Replace steering gear assembly.
10. Defective steering gear rotary
valve.10. Replace steering gear assembly.
11. Intermediate steering shaft
coupler flex joint binding.11. Replace intermediate steering
shaft/coupler.
19 - 6 STEERINGNS
DIAGNOSIS AND TESTING (Continued)
VEHICLE LEADS TO THE SIDE
POWER STEERING FLUID LEAK
CONDITION POSSIBLE CAUSES CORRECTION
STEERING WHEEL DOES NOT
WANT RETURN TO CENTER
POSITION.1. Radial tire lead. 1.Rotate tires as recommended in
the Tire And Wheel Group of this
service manual.
2. Front suspension misaligned. 2. Align the front suspension as
required. Refer to the Wheel
Alignment Procedure in the
Suspension Group of this service
manual for the required wheel
alignment procedure.
3. Wheel braking. 3. Check for dragging brakes. Refer
to the procedures in the Brake
Group of this service manual.
4. Unbalanced steering gear valve.
(If this is the cause, the steering
efforts will be very light in direction
of lead and heavier in the opposite
direction.4. Replace steering gear.
STEERING WHEEL HAS FORE
AND AFT LOOSENESS.1. Steering wheel to steering column
shaft retaining nut not properly
tightened and torqued.1. Tighten the retaining nut to its
specified torque specification.
2. Steering column lower bearing
spring retainer slipped on steering
column shaft.2. Replace steering column.
3. Loose steering column to
instrument panel mounting nuts.3. Verify that the 4 mounting nuts for
the steering column are tightened to
the specified torque.
4. Binding intermediate steering
shaft coupler.4. Disconnect intermediate steering
coupler and see if looseness no
longer exists. If yes replace
intermendiate steering coupler.
CONDITION POSSIBLE CAUSES CORRECTION
LOW FLUID LEVEL WITH: NO
VISIBLE SIGNS OF A LEAK ON
THE STEERING GEAR, POWER
STEERING PUMP, FLOOR OR
ANYWHERE ELSE.1. Overfilled power steering pump
fluid reservoir.1. Adjust the power steering fluid fill
to the correct level.
LOW FLUID LEVEL WITH:
VISIBLE LEAK ON STEERING
GEAR, POWER STEERING
PUMP, FLOOR OR ANYWHERE
ELSE.2. Power steering hose connections
at the power steering pump or
steering gear.2. Check for loose fittings and if
found, tighten the fitting to its
specified torque. If fittings are tight
examine the fittings for damaged or
missing O-ring seals and replace as
required.
3. Power steering pump or power
steering gear leaking.3. Identify the location of the leak
and repair or replace the component
as required. Refer to Power Steering
Pump and/or Power Steering Gear in
this group of the service manual for
required procedures.
NSSTEERING 19 - 7
DIAGNOSIS AND TESTING (Continued)
FOAMY OR MILKY POWER STEERING FLUID
CONDITION POSSIBLE CAUSES CORRECTION
AERATION AND OVERFLOW OF
FLUID.1. Air leaks. 1. Check for air leaking into the
power steering system as described
under Sucking Air Diagnosis and
correct condition.
2. Low fluid level. 2. Extremely cold temperatures may
cause power steering fluid aeration if
the power steering fluid is low. Add
power steering fluid as required to
bring level up to specification.
3. Cracked power steering pump
housing.3. Remove power steering pump
from vehicle and inspect the power
steering pump housing for cracks. If
a defect in the housing is found,
replace the power steering pump.
4. Water contamination. 4. Drain the power steering fluid
from the system if there is evidence
of contamination. Then refill the
system with fresh clean power
steering fluid.
19 - 8 STEERINGNS
DIAGNOSIS AND TESTING (Continued)
POWER STEERING PUMP
INDEX
page page
DESCRIPTION AND OPERATION
POWER STEERING PUMP OPERATION....... 9
DIAGNOSIS AND TESTING
POWER STEERING PUMP FLOW RATE AND
PRESSURE TEST....................... 9
SERVICE PROCEDURES
POWER STEERING PUMP INITIAL
OPERATION.......................... 10
POWER STEERING SYSTEM FLUID LEVEL
CHECK.............................. 10
REMOVAL AND INSTALLATION
2.4 LITER POWER STEERING PUMP......... 11
3.0 LITER POWER STEERING PUMP........ 13
3.3/3.8 LITER POWER STEERING PUMP...... 16
POWER STEERING FLUID PRESSURE HOSE . . 19POWER STEERING FLUID RESERVOIR TO
PUMP SUPPLY HOSE................... 18
POWER STEERING FLUID RETURN HOSE.... 21
REMOTE POWER STEERING FLUID
RESERVOIR.......................... 22
DISASSEMBLY AND ASSEMBLY
POWER STEERING PUMP FLOW CONTROL
VALVE SEAL.......................... 23
POWER STEERING PUMP PULLEY.......... 23
SPECIFICATIONS
POWER STEERING PUMP FASTENER
TORQUE SPECIFICATIONS.............. 24
POWER STEERING SYSTEM
SPECIFICATIONS...................... 24
SPECIAL TOOLS
POWER STEERING PUMP................. 25
DESCRIPTION AND OPERATION
POWER STEERING PUMP OPERATION
Hydraulic pressure for the operation of the power
steering gear is provided by a belt driven power
steering pump (Fig. 1). The power steering pump is a
constant flow rate and displacement vane type pump.
The power steering pump used on all applications is
the Vane-Submerged remote reservoir style power
steering pump.
The remote reservoir type pump (Fig. 1) has the
pump housing and internal components combined
with the fluid housing. But it has a remote reservoir
for the power steering fluid supply.
DIAGNOSIS AND TESTING
POWER STEERING PUMP FLOW RATE AND
PRESSURE TEST
The following procedure can be used to test the
operation of the power steering system on the vehi-
cle. This test will provide the flow rate of the power
steering pump along with the maximum relief pres-
sure. This test is to be performed any time a power
steering system problem is present to determine if
the power steering pump or power steering gear is
not functioning properly. The following pressure and
flow test is performed using Pressure/Flow Tester,
Special Tool 6815 (Fig. 2).
Fig. 1 Vane Submerged Remote Reservoir Power
Fig. 2 Power Steering Pump Flow/Pressure Tester
NSSTEERING 19 - 9