National 8059S Power Steering Pump Shaft Seal - Outer

Overview of National 8059S Power Steering Pump Shaft Seal

The National 8059S power steering pump shaft seal is engineered to provide reliable sealing performance for select Buick, Cadillac, Chevrolet, Oldsmobile, and Pontiac models. Designed with precision dimensions and durable nitrile material, this oil seal helps maintain system integrity and prevent fluid leaks in power steering pumps.

• Inside diameter: 0.968 inch (24.590 mm)
• Outside diameter: 1.690 inch (42.930 mm)
• Thickness/width: 0.312 inch (7.920 mm)
• Housing bore diameter: 1.686 inch (42.820 mm)
• Material: Nitrile for oil resistance and durability
• Part type: Power steering pump shaft oil seal
• Series: 8000

Detailed Product Description and Specifications

The National 8059S is a power steering pump shaft seal designed to fit a range of classic and late-model vehicles including Buick 88 and 98, Cadillac DeVille and Eldorado, Chevrolet Bel Air and Impala, Oldsmobile Starfire and 88, Pontiac Catalina and Laurentian, and more. This seal features a 0.968 inch (24.590 mm) inside diameter to fit the pump shaft precisely, while the 1.690 inch (42.930 mm) outside diameter ensures a secure fit within the housing bore of 1.686 inch (42.820 mm). The 0.312 inch (7.920 mm) thickness provides adequate sealing surface to prevent fluid leakage under operating pressures. Constructed from nitrile, the seal offers resistance to oil and heat, making it suitable for power steering systems exposed to hydraulic fluid and engine heat.

Applications and Common Issues Addressed

• Prevents power steering fluid leaks from the pump shaft area
• Maintains hydraulic pressure for consistent steering performance
• Reduces contamination ingress into the power steering pump
• Helps avoid premature pump wear caused by fluid loss
• Restores proper sealing in vehicles experiencing steering fluid seepage

Installation Notes and Tips

• Ensure the pump shaft and housing bore are clean and free of debris before installation
• Lubricate the seal lip with clean power steering fluid to ease installation and prevent damage
• Press the seal evenly into the housing bore to avoid distortion
• Verify correct orientation of the seal lip facing the fluid side
• Check for proper fitment on Buick, Cadillac, Chevrolet, Oldsmobile, and Pontiac models listed before installation

Quality Assurance and Warranty Information

National manufactures the 8059S power steering pump shaft seal to meet industry standards for durability and performance. The nitrile material and precise dimensions ensure long-lasting sealing capability under typical operating conditions. While specific warranty details may vary, National products generally come with a limited warranty against manufacturing defects. Always consult product documentation or supplier information for exact warranty terms.