Chevrolet 1980 Light Duty Truck Service Manual page 203

CONDITION
Poor return of steering. (Cont'd.)
Car leads to one side or the other.
(Keep in mind road condition and
wind. Test car on flat road going in
both directions)
Steering wheel surges or jerks when
turning with engine running especially
during parking.
Momentary increase in effort when
turning wheel fast to right or left.
Hard steering or lack of assist.
POSSIBLE CAUSE
Steering gear adjustments over
specifications.
Sticky or plugged valve spool.
Rubber spacer binding in shift tube.
Improper front suspension alignment.
Tight steering shaft bearings.
Front suspension misaligned
Steering shaft rubbing ID of shift tube.
Unbalanced or badly worn steering
gear valve.
If this is cause, steering effort
NOTE:
will be very light in direction of lead
and heavy in opposite direction.
Steering linkage not level.
Low oil level in pump.
Loose pump belt.
Sticky flow control valve.
Insufficient pump pressure.
Steering linkage hitting engine oil pan
at full turn.
Pump belt slipping.
Low oil level in pump.
High internal leakage.
High internal leakage. (Gear or pump)
Loose pump belt.
Low oil level in reservoir.
Fig. 3 B 3 -4 ~ P o w e r Steering Diagnosis C hart C
POWER STEERING SYSTEM
CORRECTION
Check adjustment with pitman arm
disconnected. Readjust if necessary.
Remove and clean or replace valve.
Make certain spacer is properly seated.
Lubricate inside diameter with sili­
cone lubricant.
Check and adjust to specifications.
Replace bearings.
Adjust to specifications.
Align column.
Replace valve.
Adjust as required.
Check oil level, add as necessary
Adjust tension to specification.
Inspect for varnish or damage, replace
if necessary.
Check pump pressure. (See pump
pressure test). Replace relief valve if
defective.
Correct clearance.
Tighten or replace belt.
Check oil level, add as necessary.
Check pump pressure (Test)
Check pump pressure. (See pump
pressure test).
Adjust belt tension to specification.
Fill to proper level. If excessively low,
check all lines and joints for evidence
of external leakage, torque to specs.
3B3-5
LIG H T T R U C K S ER V IC E MANUAL