GM Service Manual Online
For 1990-2009 cars only

Hissing Noise

    â€¢ Under normal conditions some noise may be heard during stationary maneuvering.
    â€¢ Inspect for hydraulic leak.
    â€¢ Inspect for air in the power steering system.

Momentary High Effort When Turning Wheel Quickly

    â€¢ Inspect for internal pressure leak.
    â€¢ Inspect for insufficient pump pressure.
    â€¢ Inspect for low fluid level.