

The Fluid Section Pump Cylinder is the hardened housing in the pump’s fluid section. It contains the packings and guides the piston/rod assembly to generate consistent high-pressure flow. Replacing a worn cylinder restores pressure, improves spray quality, and reduces premature packing wear.
| Attribute | Value |
|---|---|
| OEM Brand | Graco |
| Part Number | 16X458 |
| Component | Fluid Section Pump Cylinder |
| Compatible Series | TexSpray Mark X, TexSpray 7900 HD, GMAX II 7900HD |
| Typical Symptoms of Wear | Pressure drop, uneven spray pattern, frequent packing failures, scoring inside cylinder |
| Recommended Checks | Inspect piston rod surface, packings, balls/seats; verify correct lube and flush fluid after use |
No. The 16X458 is the cylinder only. Packings, balls/seats, and other wear parts are typically sold in separate repair kits for the compatible pumps.
Check your sprayer’s manual for the fluid section/pump assembly bill of materials and verify 16X458 by part number. If you have a serial number, cross-reference the production year/sub-series in the manual or contact support for confirmation.
Inspect the piston rod for scoring, replace packings, and check inlet/outlet balls and seats. Confirm proper lubricant and perform a full system flush after reassembly.
Multiple distributor fitment lists include GMAX II 7900HD, in addition to TexSpray Mark X and TexSpray 7900 HD. Always verify your pump sub-assembly to be sure.