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1977 PONTIAC SERVICE MANUAL
Rattle or Chuckle Ndise i n Steering Gear
1. Pressure hose touching other parts of car.
2. Loose pitman shaft over center adjustment.
NOTE: A slight rattle may occur on turns because of
increased clearance off the "high point". This is normal
and clearance must not be reduced below specified limits
to eliminate this slight rattle.
Squawk Noise i n Steering Gear When Turning or
Recovering From a Turn
1. Dampener
"0"
ring on valve spool cut.
Growl Noise i n Steering Pump
1. Excessive back pressure in hoses or steering gear
caused by restriction.
Growl Noise i n Steering Pump (Particularly
Noticeable a t Standstill Parking)
1. Scored pressure plates, thrust plate or rotor.
2. Extreme wear of cam ring.
Groan Noise i n Steering Pump
1. Air in the oil. Poor pressure hose connection.
Rattle Noise i n Steering Pump
1. Vanes not installed properly.
2. Vanes sticking in rotor slots.
Swish Noise i n Steering Pump
1. Defective flow control valve.
Whine Noise in Steering Pump
1. Pump shaft bearing scored.
Poor Return of Steering Wheel t o Center
1. Steering wheel rubbing against directional signal
housing.
2. Lower coupling flange rubbing against steering gear
adjuster plug.
3. Tight or frozen steering shaft bearings.
4. Steering gear adjustments over specifications.
5. Sticky or plugged spool valve.
Momentary Increase i n Effort When Turning
Wheel Fast t o Right or Left.
1. High internal leakage.
Steering Wheel Surges or Jerks When Turning
w i t h Engine Running (Especially During Parking)
1. Steering linkage hitting engine oil pan at full turn.
2. Insufficient pump pressure.
3. Sticky flow control valve.
Excessive Wheel Kick-Back or Loose Steering
1. Air in system.
2. Steering gear flexible coupling loose on shaft or rubber
disc mounting nuts loose.
3. Worn poppet valve (gear).
4. Loose thrust bearing preload adjustment (gear).
5. Excessive "over-center" lash.
Hard Steering or Lack of Assist (Especially
During Parking)
1. Brakes applied when parking.
2. Lower coupling flange rubbing against steering gear
adjuster plug.
3. Sticky flow control valve.
4.
Insufficient pump pressure output.
5. Excessive internal pump leakage.
6. Excessive internal gear leakage.
Low Pressure Due t o Steering Pump
1. Flow control valve stuck or inoperative.
2. Pressure plate not flat against cam ring.
3. Extreme wear of cam ring.
4. Scored pressure plate, thrust plate or rotor.
5. Vanes not installed properly.
6. Vanes sticking in rotor slots.
7. Cracked or broken thrust or pressure plate.
Foaming Milky Power Steering Fluid, Low Fluid
Level and Possible Low Pressure
I. Air in the fluid and loss of fluid due to internal pump
leakage causing overflow. Check for leak and correct. Bleed
system. Extremely cold temperatures will cause system
aeration should the oil level be low. If oil level is correct and
pump still foams, remove pump from car and separate
reservoir from housing. Check welsh plug and housing for
cracks. If plug is loose or housing is cracked, replace housing.
Low Pressure Due t o Steering Gear
1. Pressure loss in cylinder due to worn piston ring or
scored housing bore.
2. Leakage at valve rings, valve body to worm seal.
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