The pressure plate is not flat against the cam ring.

Replace the pressure plate.

The cam ring is extremely worn.

1. Replace the ring.
2. Flush the system.

Refer to Power Steering System Flushing .

The following components are scored:

1. Replace the components. If the rotator is scored, replace the rotor with a rotating group.
2. Flush the system. Refer to Power Steering System Flushing .

The vanes are sticking in the rotor slots.

Remove the following obstructions in order to loosen the vanes:

The vanes are not properly installed.

Install the vanes properly, with the radius edge to the outside.

Air is in the oil.

1. Correct the leak.
2. Bleed the system.

Refer to Power Steering System Bleeding .

The oil level is low.

Add power steering fluid as required. Refer to Checking and Adding Power Steering Fluid .

The pump belt is slipping.

Refer to Drive Belt Replacement in Engine mechanical 4.3L.

The drive belt tensioner is weak.

Refer to Drive Belt Tensioner Diagnosis in Engine Mechanical 4.3L.

The hoses or the steering gear is damaged.

Replace the components as necessary.