* Cavitation: The pump is designed to move fluid, not air. When the fluid level is low, air gets sucked into the pump. This causes cavitation – the formation and collapse of air bubbles within the pump. The collapsing bubbles create shock waves that severely erode the pump's internal components, particularly the vanes and housing. This erosion leads to reduced efficiency and eventual pump failure.
* Overheating: The pump works harder to create pressure when there's insufficient fluid. This increased workload generates excessive heat, which can damage seals, bearings, and other internal parts. The heat can also degrade the fluid itself, further compounding the problem.
* Seizure: Extreme low fluid levels can lead to complete pump seizure. Without enough fluid to lubricate the moving parts, friction increases dramatically, causing the pump to overheat and lock up. This often requires complete pump replacement.
* Worn-out seals: The lack of proper lubrication due to low fluid can cause the seals within the pump to wear out prematurely, leading to further fluid loss and internal leakage.
In short, running a power steering pump with low fluid is a recipe for disaster. It's far cheaper to prevent the problem by regularly checking and topping up your power steering fluid than to replace a damaged pump.
