GMC 1986 P-Truck Service Manual page 212

3B3-6 POWER STEERING
DIAGNOSIS OF POWER STEERING SYSTEM (CONT.)
PROBLEM
Vehicle Leads To
One Side Or The
Other (Keep In Mind
The Road And Wind
Conditions). Test
The Vehicle, Going
In Both Directions,
On A Flat Road.
Momentary Increase
In Effort When
Turning The Wheel
Q uickly To The Right
Or Left
Poor Return Of
Steering
10. Rubber spacer binding in the shift
11. Improper front end alignment.
12. Tight steering shaft bearings.
13. Steering gear adjusted too tightly.
14. Kink in return hose.
Steering Wheel
Surges Or Jerks
When Turning With
Engine Running
Especially During
Parking
Hard Steering Effort
In Both Directions
POSSIBLE CAUSE
1. Front end misaligned.
2. Unbalanced steering gear valve. If this
is cause, steering effort will be very
light in direction of lead and heavy in
opposite direction.
3. Steering shaft rubbing the ID of the
shaft tube.
4. Steering linkage not level.
1. Low oil level in the pump.
2. Pump belt slipping (if used).
3. High internal linkage (steering gear or
pump).
1. Tires under-inflated.
2. Lower coupling flange rubbing against
the steering gear adjuster plug.
3. Steering wheel rubbing against direc­
tional signal housing.
4. Tight or frozen steering shaft bearings.
5. Steering linkage or ball joints binding.
6. Steering gear to column misalignment.
7. Tie rod pivots not centralized.
8. Lack of lubricant in the suspension
ball joints and the steering linkage.
9. Sticky or plugged valve spool.
tube.
1. Low oil level in pump.
2. Loose pump belt.
3. Sticky flow control valve.
4. Insufficient pump pressure.
5. Faulty gear relief valve.
1. Low tire pressure.
2. Lack of lubricant in suspension or ball
joints.
3. Steering gear to column misalignment.
4. Loose pump belt.
CORRECTION
1. Adjust to specifications.
2. Replace the gear valve.
3. Align the column.
4. Adjust as required.
1. Add power steering fluid as required.
2. Tighten or replace belt.
3. Refer to " Power Steering System
Test" in this section.
1. Inflate to specified pressure.
2. Loosen the pinch bolt and assemble
properly.
3. Adjust the steering jacket.
4. Replace the bearings.
5. Replace the affected parts.
6. Align the steering column.
7. Adjust tie rod ends as required to
center pivots.
8. Lubricate. Refer to MAINTENANCE
AND LUBRICATION (SEC. OB).
9. Remove and clean or replace the
valve.
10. Make certain the spacer is properly
seated. Lubricate inside the diameter
with silicone lubricant.
11. Check and adjust to specifications.
12. Replace the bearings.
13. Adjust over-center and thrust bearing
preload to specifications.
14. Replace the hose.
1. Add power steering fluid as required.
2. Adjust tension to specification.
3. Replace or clean the control valve.
4. Refer to " Power Steering System
Test" in this section.
5. Replace the gear relief valve.
1. Adjust the tire pressure.
2. Lubricate and relubricate at proper
intervals. Refer to MAINTENANCE
AND LUBRICATION (SEC. OB).
3. Align the steering column.
4. Adjust belt tension to specifications.