Cold Weather Hard Steer Tech Tip

Hard steer during cold start-up has been a frustrating problem with power racks since the beginning. GM has had its fair share of cold steering problems that would subside moments later, and the system would return to normal power assist. Internal seal seepage or leakage has been a problem since the early 80’s. Revised seals were made available, and eventually new rack assemblies were recommended for those with worn or grooved housings, thus promoting internal leakage.
How about a fluid transfusion? In addition to housing wear or seal seepage, low ambient temperatures that affect the viscosity of the fluid can contribute to hard cold weather steer. GM has a revised power steering fluid which will reduce hard steering conditions at low ambient temperatures. This fluid is appropriate for all GM passenger cars, but particularly beneficial for those applications built in the early 80’s and on that are equipped with power rack and pinion steering.
All vehicles equipped with power steering may exhibit a certain degree of hard cold steer. This condition is more pronounced at low ambient temperatures. Many vehicles with power steering experience this condition in varying degrees, but it is more pronounced with the power rack and pinion steering systems, primarily due to longer hoses or lines. This condition may be prompted by the viscosity of the fluid instead of damaged seals or housing scoring or wear.
The viscosity of the power steering fluid changes in the cold conditions in the same manner as any other petroleum based oil or fluid. During a cold start, the cold, thick fluid resists movement through the system, thus a hard steering effort is encountered. When the fluid travels through the system, the fluid warms and thins. When this occurs, the steering assist returns to normal.

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