Graco 331409 Suction Seat Assembly Lo-Boy

Compatible Machines

• Graco Ultra Max II 390 Lo-Boy
• Graco Ultra Max II 455 Lo-Boy
• Graco Lo-Boy Series Airless Paint Sprayers

Graco 331409 Suction Seat Assembly Lo-Boy

The Graco 331409 Suction Seat Assembly Lo-Boy is an original OEM replacement component designed for Lo-Boy style airless paint sprayer pumps. This part forms a critical sealing surface inside the pump’s suction valve, allowing material to flow smoothly into the pump while preventing backflow during operation.

A properly functioning suction seat is essential for maintaining consistent pressure, reliable priming, and efficient material transfer. Worn or damaged suction seats can lead to pressure loss, poor spray performance, or priming issues.

Key Functions & Benefits

• Ensures a tight seal within the pump inlet valve
• Helps maintain steady suction and fluid flow
• Supports proper priming and pressure stability
• OEM precision fit for Lo-Boy pump configurations
• Designed for durability in professional spraying environments

Product Specifications

When Should This Part Be Replaced?

Replacement is recommended if your sprayer experiences difficulty priming, inconsistent pressure, paint backflow, or reduced spray performance. Routine inspection during pump maintenance helps prevent unexpected downtime.

Frequently Asked Questions